Description

求[A,B]之间的质数个数，并且满足X=Q^2+P^2,P,Q是正整数。

Input

第一行输入A，B

Output

输出有多少组P，Q满足条件

Sample Input

6 66

Sample Output

7

HINT

1<=A<=B<=3*10^8


解法：不会做，分块打表大法好。。打表打了半小时。。


#include <bits/stdc++.h>
using namespace std;

const int t[] = {0, 4784, 8978, 12981, 16901, 20732, 24523, 28249, 31916, 35585, 39176, 42818, 46430, 49962, 53516, 57023, 60523, 64040, 67489, 70985, 74417, 77879, 81285, 84679, 88055, 91433, 94878, 98240, 101608, 104979, 108284, 111653, 115039, 118375, 121695, 124997, 128270, 131626, 134912, 138219, 141503, 144830, 148121, 151368, 154619, 157925, 161166, 164444, 167675, 170946, 174194, 177433, 180617, 183844, 187048, 190283, 193493, 196709, 199900, 203111, 206333, 209526, 212732, 215966, 219123, 222272, 225463, 228651, 231844, 235069, 238261, 241443, 244581, 247733, 250868, 253974, 257141, 260352, 263482, 266623, 269760, 272885, 276014, 279149, 282271, 285396, 288556, 291710, 294878, 297984, 301101, 304177, 307326, 310444, 313579, 316642, 319813, 322904, 326007, 329106, 332181, 335268, 338394, 341465, 344551, 347665, 350739, 353840, 356909, 360000, 363080, 366160, 369261, 372328, 375439, 378518, 381635, 384728, 387817, 390920, 393993, 397033, 400087, 403209, 406288, 409309, 412333, 415431, 418499, 421556, 424569, 427583, 430660, 433680, 436753, 439791, 442818, 445857, 448901, 451962, 454974, 457972, 461015, 464069, 467135, 470153, 473178, 476215, 479250, 482265, 485275, 488279, 491293, 494311, 497242, 500236, 503251, 506276, 509308, 512383, 515414, 518404, 521398, 524428, 527422, 530472, 533469, 536442, 539450, 542467, 545501, 548499, 551461, 554513, 557493, 560489, 563514, 566514, 569508, 572481, 575503, 578464, 581445, 584484, 587448, 590416, 593357, 596373, 599365, 602379, 605357, 608340, 611346, 614316, 617284, 620283, 623219, 626204, 629187, 632137, 635171, 638124, 641088, 644018, 646968, 649933, 652929, 655897, 658857, 661819, 664771, 667743, 670676, 673688, 676670, 679672, 682576, 685541, 688504, 691478, 694490, 697405, 700326, 703273, 706181, 709115, 712113, 715038, 717989, 720960, 723896, 726882, 729831, 732782, 735740, 738676, 741606, 744563, 747458, 750384, 753318, 756217, 759188, 762199, 765150, 768087, 771012, 773928, 776896, 779827, 782754, 785698, 788611, 791513, 794449, 797361, 800286, 803241, 806180, 809116, 812028, 814963, 817868, 820796, 823752, 826720, 829643, 832596, 835498, 838436, 841364, 844292, 847194, 850080, 853022, 855895, 858875, 861761, 864672, 867592, 870514, 873482, 876358, 879282, 882186, 885138, 888023, 890933, 893857, 896758, 899686, 902573, 905460, 908421, 911332, 914214, 917110, 920007, 922881, 925822, 928780, 931678, 934604, 937520, 940453, 943326, 946295, 949181, 952088, 955026, 957871, 960726, 963624, 966507, 969407, 972309, 975196, 978085, 980962, 983867, 986746, 989647, 992538, 995405, 998272, 1001141, 1004047, 1006935, 1009828, 1012698, 1015619, 1018497, 1021407, 1024321, 1027185, 1030064, 1032962, 1035803, 1038722, 1041665, 1044521, 1047338, 1050175, 1053074, 1055897, 1058798, 1061676, 1064500, 1067388, 1070268, 1073174, 1076029, 1078883, 1081790, 1084692, 1087554, 1090413, 1093331, 1096221, 1099056, 1101903, 1104801, 1107645, 1110568, 1113425, 1116309, 1119226, 1122066, 1124941, 1127772, 1130652, 1133559, 1136475, 1139334, 1142195, 1145026, 1147867, 1150738, 1153592, 1156490, 1159339, 1162244, 1165140, 1168043, 1170911, 1173746, 1176591, 1179444, 1182370, 1185244, 1188093, 1190925, 1193801, 1196660, 1199545, 1202432, 1205285, 1208198, 1211026, 1213868, 1216688, 1219588, 1222393, 1225259, 1228119, 1230996, 1233830, 1236682, 1239605, 1242422, 1245272, 1248112, 1250996, 1253792, 1256652, 1259537, 1262363, 1265205, 1268047, 1270890, 1273689, 1276506, 1279377, 1282286, 1285127, 1287980, 1290771, 1293580, 1296434, 1299249, 1302081, 1304899, 1307765, 1310565, 1313437, 1316314, 1319179, 1321953, 1324799, 1327680, 1330570, 1333417, 1336222, 1339091, 1341880, 1344730, 1347558, 1350402, 1353252, 1356098, 1358925, 1361746, 1364529, 1367411, 1370266, 1373089, 1375934, 1378787, 1381608, 1384448, 1387240, 1390062, 1392850, 1395709, 1398555, 1401374, 1404179, 1407069, 1409899, 1412745, 1415626, 1418381, 1421271, 1424100, 1426913, 1429775, 1432595, 1435430, 1438258, 1441129, 1443939, 1446779, 1449605, 1452383, 1455248, 1458083, 1460920, 1463729, 1466529, 1469369, 1472195, 1475031, 1477838, 1480667, 1483501, 1486323, 1489166, 1491981, 1494787, 1497648, 1500453, 1503239, 1506081, 1508873, 1511686, 1514527, 1517367, 1520184, 1523011, 1525806, 1528622, 1531402, 1534201, 1536997, 1539894, 1542683, 1545503, 1548241, 1551093, 1553884, 1556702, 1559565, 1562352, 1565117, 1567943, 1570716, 1573536, 1576359, 1579176, 1581960, 1584772, 1587542, 1590356, 1593212, 1596005, 1598783, 1601564, 1604386, 1607165, 1609974, 1612824, 1615617, 1618452, 1621217, 1624007, 1626767, 1629636, 1632421, 1635222, 1637991, 1640857, 1643718, 1646485, 1649297, 1652064, 1654854, 1657619, 1660460, 1663265, 1666081, 1668892, 1671700, 1674594, 1677356, 1680125, 1682935, 1685691, 1688539, 1691341, 1694101, 1696863, 1699639, 1702441, 1705278, 1708110, 1710912, 1713725, 1716510, 1719267, 1722095, 1724880, 1727671, 1730436, 1733217, 1736052, 1738807, 1741642, 1744421, 1747205, 1750007, 1752772, 1755537, 1758337, 1761093, 1763839, 1766647, 1769444, 1772246, 1775046, 1777876, 1780671, 1783464, 1786236, 1789019, 1791841, 1794680, 1797448, 1800274, 1803074, 1805871, 1808647, 1811416, 1814143, 1816933, 1819707, 1822528, 1825244, 1828005, 1830793, 1833548, 1836360, 1839214, 1841996, 1844792, 1847581, 1850327, 1853089, 1855856, 1858663, 1861433, 1864207, 1866991, 1869796, 1872540, 1875345, 1878117, 1880878, 1883646, 1886490, 1889297, 1892075, 1894867, 1897679, 1900521, 1903296, 1906069, 1908797, 1911589, 1914346, 1917129, 1919906, 1922737, 1925489, 1928318, 1931029, 1933873, 1936618, 1939421, 1942195, 1944975, 1947727, 1950518, 1953327, 1956076, 1958882, 1961653, 1964430, 1967231, 1969999, 1972724, 1975510, 1978238, 1981017, 1983809, 1986618, 1989438, 1992205, 1994950, 1997721, 2000489, 2003304, 2006033, 2008816, 2011607, 2014373, 2017180, 2019933, 2022702, 2025513, 2028256, 2031020, 2033803, 2036610, 2039323, 2042136, 2044905, 2047682, 2050502, 2053230, 2055971, 2058719, 2061484, 2064275, 2067035, 2069780, 2072561, 2075349, 2078104, 2080845, 2083584, 2086330, 2089097, 2091864, 2094672, 2097407, 2100185, 2102972, 2105738, 2108433, 2111259, 2113990, 2116784, 2119527, 2122304, 2125069, 2127838, 2130618, 2133419, 2136173, 2138962, 2141713, 2144481, 2147172, 2149924, 2152702, 2155442, 2158237, 2161008, 2163758, 2166537, 2169247, 2171965, 2174706, 2177470, 2180269, 2183018, 2185806, 2188547, 2191332, 2194100, 2196835, 2199596, 2202324, 2205083, 2207860, 2210669, 2213444, 2216182, 2218953, 2221739, 2224515, 2227246, 2230006, 2232708, 2235482, 2238231, 2240991, 2243756, 2246480, 2249227, 2252025, 2254788, 2257554, 2260312, 2263079, 2265828, 2268545, 2271245, 2274003, 2276736, 2279483, 2282217, 2284983, 2287747, 2290512, 2293240, 2295997, 2298702, 2301494, 2304177, 2306931, 2309704, 2312443, 2315163, 2317910, 2320691, 2323417, 2326186, 2328942, 2331676, 2334374, 2337139, 2339871, 2342642, 2345411, 2348163, 2350887, 2353608, 2356373, 2359139, 2361872, 2364678, 2367432, 2370149, 2372878, 2375651, 2378388, 2381162, 2383896, 2386653, 2389450, 2392222, 2394902, 2397618, 2400363, 2403099, 2405857, 2408603, 2411351, 2414127, 2416904, 2419627, 2422296, 2425056, 2427745, 2430503, 2433251, 2436001, 2438719, 2441528, 2444352, 2447016, 2449765, 2452482, 2455256, 2458031, 2460744, 2463429, 2466187, 2468912, 2471679, 2474403, 2477113, 2479832, 2482617, 2485399, 2488154, 2490869, 2493631, 2496331, 2499026, 2501804, 2504528, 2507234, 2509986, 2512726, 2515473, 2518175, 2520875, 2523614, 2526330, 2529122, 2531839, 2534604, 2537308, 2540008, 2542791, 2545541, 2548284, 2551055, 2553802, 2556546, 2559256, 2562021, 2564750, 2567510, 2570148, 2572929, 2575664, 2578403, 2581128, 2583836, 2586615, 2589384, 2592090, 2594819, 2597536, 2600254, 2602944, 2605706, 2608394, 2611086, 2613806, 2616565, 2619321, 2622048, 2624787, 2627470, 2630206, 2632916, 2635613, 2638344, 2641068, 2643874, 2646581, 2649274, 2651923, 2654664, 2657389, 2660089, 2662840, 2665564, 2668329, 2671039, 2673788, 2676540, 2679254, 2682014, 2684761, 2687515, 2690185, 2692884, 2695614, 2698331, 2701067, 2703798, 2706497, 2709174, 2711871, 2714585, 2717374, 2720152, 2722854, 2725559, 2728236, 2730937, 2733698, 2736447, 2739146, 2741927, 2744682, 2747379, 2750078, 2752811, 2755521, 2758290, 2761026, 2763725, 2766426, 2769153, 2771910, 2774616, 2777363, 2780032, 2782759, 2785459, 2788181, 2790935, 2793661, 2796375, 2799109, 2801844, 2804531, 2807261, 2809930, 2812655, 2815400, 2818088, 2820817, 2823539, 2826276, 2828967, 2831689, 2834417, 2837100, 2839799, 2842571, 2845296, 2847955, 2850686, 2853362, 2856131, 2858814, 2861494, 2864215, 2866912, 2869649, 2872353, 2875061, 2877770, 2880505, 2883226, 2885940, 2888661, 2891324, 2894042, 2896737, 2899482, 2902173, 2904857, 2907606, 2910319, 2913026, 2915749, 2918453, 2921165, 2923834, 2926597, 2929265, 2931966, 2934703, 2937422, 2940118, 2942867, 2945636, 2948312, 2951035, 2953764, 2956447, 2959193, 2961881, 2964616, 2967240, 2969938, 2972638, 2975367, 2978051, 2980755, 2983431, 2986123, 2988902, 2991612, 2994331, 2997075, 2999799, 3002504, 3005203, 3007900, 3010597, 3013324, 3016009, 3018743, 3021417, 3024129, 3026843, 3029542, 3032258, 3034938, 3037647, 3040326, 3043022, 3045754, 3048458, 3051170, 3053831, 3056533, 3059268, 3061963, 3064626, 3067352, 3069997, 3072755, 3075490, 3078186, 3080941, 3083637, 3086305, 3089049, 3091766, 3094461, 3097083, 3099791, 3102503, 3105214, 3107929, 3110676, 3113376, 3116121, 3118822, 3121506, 3124226, 3126914, 3129663, 3132389, 3135041, 3137800, 3140465, 3143179, 3145895, 3148595, 3151359, 3154060, 3156704, 3159381, 3162037, 3164764, 3167422, 3170165, 3172860, 3175583, 3178276, 3180981, 3183679, 3186336, 3189067, 3191741, 3194439, 3197144, 3199905, 3202633, 3205350, 3208093, 3210815, 3213514, 3216212, 3218845, 3221531, 3224234, 3226984, 3229664, 3232326, 3235040, 3237756, 3240412, 3243108, 3245793, 3248448, 3251142, 3253794, 3256465, 3259118, 3261786, 3264499, 3267184, 3269881, 3272566, 3275208, 3277990, 3280684, 3283348, 3286023, 3288733, 3291422, 3294158, 3296809, 3299511, 3302209, 3304882, 3307587, 3310219, 3312951, 3315658, 3318340, 3321024, 3323750, 3326372, 3329060, 3331730, 3334387, 3337067, 3339778, 3342472, 3345126, 3347848, 3350545, 3353226, 3355956, 3358630, 3361303, 3363969, 3366670, 3369387, 3372104, 3374796, 3377477, 3380175, 3382885, 3385555, 3388181, 3390855, 3393551, 3396270, 3398959, 3401658, 3404348, 3407022, 3409749, 3412424, 3415112, 3417799, 3420476, 3423164, 3425804, 3428513, 3431140, 3433831, 3436495, 3439209, 3441873, 3444597, 3447272, 3450005, 3452685, 3455326, 3458010, 3460716, 3463433, 3466044, 3468740, 3471402, 3474095, 3476807, 3479443, 3482094, 3484813, 3487498, 3490171, 3492860, 3495568, 3498297, 3500974, 3503652, 3506387, 3509080, 3511783, 3514444, 3517154, 3519834, 3522520, 3525176, 3527908, 3530582, 3533256, 3535969, 3538668, 3541338, 3543978, 3546667, 3549376, 3552022, 3554739, 3557385, 3560090, 3562780, 3565457, 3568117, 3570777, 3573441, 3576162, 3578838, 3581527, 3584202, 3586899, 3589608, 3592224, 3594895, 3597609, 3600284, 3602937, 3605598, 3608315, 3611057, 3613719, 3616375, 3619063, 3621779, 3624437, 3627138, 3629813, 3632494, 3635172, 3637897, 3640546, 3643225, 3645881, 3648522, 3651242, 3653950, 3656685, 3659419, 3662084, 3664727, 3667446, 3670105, 3672775, 3675493, 3678172, 3680848, 3683590, 3686168, 3688865, 3691503, 3694149, 3696775, 3699495, 3702151, 3704779, 3707476, 3710195, 3712861, 3715571, 3718229, 3720907, 3723622, 3726326, 3729014, 3731697, 3734399, 3737057, 3739687, 3742387, 3745052, 3747736, 3750447, 3753093, 3755763, 3758470, 3761125, 3763798, 3766488, 3769101, 3771838, 3774512, 3777096, 3779799, 3782494, 3785161, 3787804, 3790455, 3793100, 3795810, 3798471, 3801142, 3803841, 3806532, 3809252, 3811893, 3814570, 3817240, 3819899, 3822594, 3825303, 3827949, 3830626, 3833257, 3835966, 3838551, 3841206, 3843893, 3846531, 3849184, 3851821, 3854488, 3857123, 3859809, 3862541, 3865213, 3867908, 3870566, 3873197, 3875855, 3878498, 3881127, 3883820, 3886491, 3889196, 3891882, 3894547, 3897254, 3899883, 3902460, 3905110, 3907779, 3910369, 3913050, 3915712, 3918400, 3921049, 3923696, 3926401, 3929085, 3931738, 3934443, 3937079, 3939772, 3942498, 3945191, 3947875, 3950555, 3953194, 3955921, 3958645, 3961297, 3963906, 3966568, 3969211, 3971880, 3974536, 3977155, 3979753, 3982460, 3985072, 3987720, 3990416, 3993126, 3995735, 3998438, 4001109, 4003807, 4006464, 4009128, 4011827, 4014469, 4017140, 4019846, 4022481, 4025096, 4027765, 4030424, 4033095, 4035734, 4038441, 4041068, 4043777, 4046464, 4049121, 4051770, 4054424, 4057114, 4059771, 4062451, 4065123, 4067794, 4070475, 4073176, 4075821, 4078473, 4081177, 4083782, 4086435, 4089090, 4091774, 4094421, 4097099, 4099748, 4102417, 4105056, 4107702, 4110356, 4113050, 4115722, 4118385, 4121052, 4123728, 4126380, 4129050, 4131700, 4134353, 4137024, 4139686, 4142364, 4145061, 4147677, 4150324, 4153011, 4155686, 4158364, 4160967, 4163597, 4166236, 4168923, 4171606, 4174224, 4176870, 4179522, 4182183, 4184850, 4187489, 4190141, 4192811, 4195422, 4198063, 4200732, 4203355, 4206045, 4208687, 4211357, 4213982, 4216686, 4219357, 4221985, 4224628, 4227283, 4229915, 4232565, 4235233, 4237862, 4240503, 4243170, 4245785, 4248402, 4251066, 4253702, 4256360, 4259015, 4261661, 4264294, 4266922, 4269625, 4272264, 4274957, 4277598, 4280202, 4282798, 4285399, 4288065, 4290688, 4293351, 4296021, 4298654, 4301295, 4303982, 4306609, 4309218, 4311887, 4314529, 4317235, 4319923, 4322593, 4325294, 4327912, 4330591, 4333234, 4335879, 4338516, 4341144, 4343802, 4346451, 4349053, 4351735, 4354389, 4357049, 4359663, 4362342, 4364926, 4367588, 4370299, 4372936, 4375553, 4378193, 4380845, 4383575, 4386240, 4388879, 4391542, 4394200, 4396851, 4399521, 4402187, 4404832, 4407487, 4410086, 4412694, 4415371, 4418023, 4420721, 4423372, 4425992, 4428609, 4431243, 4433902, 4436580, 4439170, 4441823, 4444490, 4447138, 4449673, 4452307, 4454923, 4457555, 4460241, 4462894, 4465544, 4468140, 4470785, 4473457, 4476148, 4478750, 4481417, 4484076, 4486724, 4489312, 4492007, 4494652, 4497293, 4499966, 4502619, 4505253, 4507856, 4510573, 4513194, 4515919, 4518560, 4521186, 4523774, 4526427, 4529073, 4531708, 4534347, 4536968, 4539593, 4542204, 4544861, 4547523, 4550196, 4552844, 4555492, 4558141, 4560804, 4563438, 4566061, 4568706, 4571337, 4574015, 4576657, 4579285, 4581977, 4584687, 4587326, 4589993, 4592654, 4595266, 4597877, 4600572, 4603201, 4605817, 4608469, 4611140, 4613737, 4616385, 4619006, 4621593, 4624232, 4626876, 4629508, 4632187, 4634797, 4637399, 4640031, 4642678, 4645360, 4647919, 4650560, 4653231, 4655889, 4658586, 4661190, 4663804, 4666451, 4669055, 4671705, 4674351, 4676997, 4679633, 4682243, 4684949, 4687533, 4690161, 4692790, 4695463, 4698103, 4700735, 4703363, 4706007, 4708643, 4711274, 4713900, 4716608, 4719202, 4721853, 4724481, 4727184, 4729855, 4732496, 4735168, 4737851, 4740486, 4743083, 4745721, 4748367, 4750950, 4753627, 4756289, 4758913, 4761561, 4764205, 4766823, 4769430, 4772013, 4774673, 4777296, 4779967, 4782597, 4785262, 4787905, 4790546, 4793167, 4795770, 4798436, 4801064, 4803668, 4806333, 4808985, 4811623, 4814267, 4816891, 4819529, 4822161, 4824805, 4827436, 4830058, 4832685, 4835379, 4838000, 4840681, 4843322, 4845982, 4848640, 4851212, 4853838, 4856492, 4859127, 4861763, 4864388, 4867028, 4869676, 4872296, 4874854, 4877529, 4880180, 4882798, 4885427, 4888078, 4890746, 4893365, 4896011, 4898673, 4901286, 4903891, 4906512, 4909157, 4911785, 4914384, 4917033, 4919690, 4922306, 4924919, 4927573, 4930213, 4932818, 4935488, 4938140, 4940775, 4943379, 4946070, 4948680, 4951297, 4953911, 4956558, 4959210, 4961878, 4964538, 4967185, 4969806, 4972410, 4975039, 4977662, 4980311, 4982941, 4985647, 4988226, 4990898, 4993516, 4996145, 4998802, 5001443, 5004057, 5006709, 5009406, 5012065, 5014695, 5017340, 5019950, 5022572, 5025179, 5027802, 5030447, 5033047, 5035681, 5038280, 5040863, 5043508, 5046095, 5048766, 5051412, 5054025, 5056629, 5059278, 5061913, 5064512, 5067205, 5069825, 5072492, 5075114, 5077659, 5080256, 5082860, 5085500, 5088135, 5090728, 5093333, 5095989, 5098616, 5101203, 5103826, 5106459, 5109090, 5111744, 5114362, 5116967, 5119591, 5122214, 5124845, 5127515, 5130154, 5132783, 5135431, 5138076, 5140731, 5143346, 5145981, 5148606, 5151275, 5153900, 5156547, 5159150, 5161734, 5164342, 5166954, 5169574, 5172232, 5174885, 5177522, 5180106, 5182723, 5185364, 5187966, 5190596, 5193213, 5195881, 5198500, 5201126, 5203797, 5206415, 5209050, 5211713, 5214289, 5216846, 5219488, 5222091, 5224741, 5227387, 5230075, 5232642, 5235256, 5237883, 5240497, 5243171, 5245787, 5248349, 5250964, 5253604, 5256295, 5258925, 5261560, 5264198, 5266812, 5269432, 5272057, 5274678, 5277359, 5279981, 5282588, 5285176, 5287825, 5290378, 5292984, 5295576, 5298144, 5300709, 5303300, 5305965, 5308565, 5311160, 5313783, 5316423, 5319019, 5321597, 5324214, 5326785, 5329410, 5332021, 5334623, 5337228, 5339868, 5342497, 5345130, 5347796, 5350422, 5353090, 5355703, 5358368, 5360987, 5363545, 5366148, 5368777, 5371412, 5374088, 5376687, 5379310, 5381929, 5384561, 5387172, 5389785, 5392412, 5395046, 5397629, 5400260, 5402887, 5405527, 5408176, 5410794, 5413434, 5415999, 5418615, 5421235, 5423862, 5426485, 5429133, 5431730, 5434359, 5436989, 5439576, 5442164, 5444785, 5447430, 5450050, 5452630, 5455226, 5457874, 5460458, 5463064, 5465636, 5468292, 5470840, 5473438, 5476040, 5478624, 5481234, 5483862, 5486492, 5489062, 5491685, 5494277, 5496930, 5499560, 5502195, 5504849, 5507484, 5510039, 5512631, 5515229, 5517813, 5520451, 5523148, 5525740, 5528354, 5530960, 5533526, 5536136, 5538821, 5541485, 5544171, 5546787, 5549334, 5551962, 5554594, 5557156, 5559794, 5562401, 5564989, 5567668, 5570318, 5572922, 5575559, 5578173, 5580735, 5583348, 5585968, 5588600, 5591257, 5593883, 5596537, 5599126, 5601766, 5604343, 5606978, 5609544, 5612150, 5614795, 5617364, 5619974, 5622604, 5625220, 5627890, 5630520, 5633085, 5635731, 5638332, 5640958, 5643587, 5646179, 5648777, 5651328, 5653955, 5656616, 5659237, 5661891, 5664467, 5667110, 5669724, 5672315, 5674898, 5677516, 5680112, 5682698, 5685283, 5687873, 5690537, 5693138, 5695725, 5698354, 5700962, 5703597, 5706173, 5708793, 5711418, 5713948, 5716608, 5719236, 5721870, 5724432, 5727030, 5729670, 5732291, 5734927, 5737555, 5740151, 5742760, 5745303, 5747922, 5750484, 5753109, 5755700, 5758284, 5760903, 5763488, 5766103, 5768742, 5771329, 5773921, 5776526, 5779099, 5781662, 5784324, 5786983, 5789590, 5792263, 5794904, 5797482, 5800089, 5802685, 5805349, 5807963, 5810588, 5813145, 5815758, 5818375, 5820930, 5823533, 5826127, 5828742, 5831423, 5834055, 5836688, 5839332, 5841893, 5844529, 5847110, 5849741, 5852352, 5854947, 5857519, 5860154, 5862786, 5865406, 5868021, 5870662, 5873255, 5875845, 5878520, 5881140, 5883729, 5886329, 5888952, 5891561, 5894167, 5896791, 5899352, 5901946, 5904577, 5907199, 5909822, 5912399, 5914980, 5917583, 5920157, 5922796, 5925412, 5928032, 5930672, 5933314, 5935941, 5938528, 5941165, 5943777, 5946380, 5949001, 5951600, 5954206, 5956845, 5959490, 5962107, 5964740, 5967358, 5969954, 5972550, 5975142, 5977742, 5980358, 5982939, 5985529, 5988135, 5990733, 5993379, 5995955, 5998500, 6001091, 6003727, 6006283, 6008887, 6011523, 6014158, 6016757, 6019332, 6021859, 6024475, 6027082, 6029692, 6032264, 6034853, 6037496, 6040041, 6042691, 6045299, 6047914, 6050499, 6053126, 6055662, 6058265, 6060852, 6063464, 6066107, 6068704, 6071358, 6073902, 6076512, 6079117, 6081675, 6084293, 6086846, 6089462, 6092066, 6094754, 6097313, 6099890, 6102471, 6105113, 6107732, 6110282, 6112891, 6115533, 6118146, 6120762, 6123306, 6125905, 6128580, 6131219, 6133813, 6136360, 6139005, 6141600, 6144218, 6146820, 6149371, 6152008, 6154675, 6157271, 6159871, 6162461, 6164976, 6167591, 6170168, 6172803, 6175450, 6178055, 6180645, 6183213, 6185805, 6188462, 6191134, 6193761, 6196339, 6198883, 6201446, 6204006, 6206615, 6209208, 6211825, 6214485, 6217047, 6219685, 6222252, 6224827, 6227426, 6230025, 6232618, 6235254, 6237903, 6240568, 6243137, 6245745, 6248383, 6250968, 6253594, 6256157, 6258704, 6261229, 6263772, 6266353, 6268950, 6271545, 6274153, 6276725, 6279295, 6281850, 6284431, 6287079, 6289703, 6292248, 6294880, 6297458, 6300083, 6302647, 6305225, 6307854, 6310423, 6313002, 6315578, 6318146, 6320783, 6323413, 6326011, 6328577, 6331172, 6333770, 6336395, 6339009, 6341630, 6344208, 6346739, 6349347, 6351927, 6354521, 6357116, 6359727, 6362295, 6364935, 6367512, 6370124, 6372759, 6375330, 6377932, 6380538, 6383126, 6385750, 6388317, 6390928, 6393566, 6396156, 6398760, 6401309, 6403894, 6406444, 6409020, 6411621, 6414240, 6416840, 6419444, 6421985, 6424585, 6427175, 6429774, 6432352, 6434905, 6437478, 6440084, 6442694, 6445293, 6447930, 6450524, 6453111, 6455682, 6458326, 6460917, 6463538, 6466171, 6468741, 6471304, 6473882, 6476474, 6479075, 6481719, 6484300, 6486895, 6489472, 6492070, 6494656, 6497314, 6499923, 6502519, 6505097, 6507692, 6510279, 6512873, 6515451, 6518114, 6520675, 6523259, 6525868, 6528444, 6531066, 6533690, 6536273, 6538887, 6541470, 6544021, 6546672, 6549285, 6551864, 6554452, 6556996, 6559587, 6562188, 6564770, 6567411, 6569951, 6572574, 6575116, 6577700, 6580260, 6582892, 6585456, 6588087, 6590708, 6593326, 6595957, 6598515, 6601071, 6603686, 6606273, 6608834, 6611498, 6614095, 6616698, 6619295, 6621894, 6624418, 6627012, 6629605, 6632211, 6634763, 6637327, 6639847, 6642444, 6645043, 6647598, 6650124, 6652723, 6655351, 6657923, 6660525, 6663028, 6665670, 6668208, 6670804, 6673402, 6676025, 6678603, 6681238, 6683806, 6686331, 6688966, 6691555, 6694117, 6696711, 6699329, 6701946, 6704527, 6707200, 6709795, 6712367, 6714983, 6717599, 6720189, 6722794, 6725391, 6727968, 6730547, 6733134, 6735695, 6738207, 6740828, 6743394, 6745968, 6748552, 6751153, 6753724, 6756299, 6758910, 6761489, 6764062, 6766666, 6769185, 6771775, 6774395, 6776965, 6779497, 6782076, 6784634, 6787249, 6789787, 6792400, 6795031, 6797654, 6800239, 6802810, 6805406, 6807999, 6810601, 6813192, 6815770, 6818374, 6820939, 6823539, 6826057, 6828648, 6831224, 6833809, 6836379, 6838975, 6841545, 6844146, 6846743, 6849310, 6851866, 6854427, 6857053, 6859666, 6862301, 6864928, 6867491, 6870031, 6872597, 6875182, 6877737, 6880327, 6882924, 6885471, 6888050, 6890595, 6893240, 6895824, 6898361, 6900909, 6903508, 6906086, 6908592, 6911194, 6913799, 6916351, 6918938, 6921532, 6924153, 6926760, 6929345, 6932010, 6934558, 6937122, 6939699, 6942266, 6944833, 6947433, 6950048, 6952622, 6955229, 6957811, 6960447, 6963003, 6965624, 6968229, 6970814, 6973374, 6975908, 6978553, 6981142, 6983701, 6986303, 6988895, 6991452, 6994053, 6996636, 6999239, 7001827, 7004386, 7006943, 7009509, 7012092, 7014637, 7017247, 7019911, 7022468, 7025101, 7027733, 7030312, 7032873, 7035446, 7038006, 7040537, 7043119, 7045744, 7048342, 7050888, 7053483, 7056063, 7058671, 7061274, 7063885, 7066487, 7069099, 7071649, 7074208, 7076794, 7079414, 7081992, 7084585, 7087182, 7089730, 7092253, 7094829, 7097378, 7099975, 7102560, 7105136, 7107734, 7110341, 7112923, 7115505, 7118105, 7120687, 7123329, 7125909, 7128529, 7131104, 7133676, 7136261, 7138851, 7141412, 7143963, 7146532, 7149099, 7151678, 7154306, 7156895, 7159502, 7162172, 7164744, 7167291, 7169862, 7172477, 7175070, 7177687, 7180299, 7182859, 7185447, 7188010, 7190543, 7193111, 7195725, 7198306, 7200837, 7203410, 7206026, 7208623, 7211221, 7213777, 7216339, 7218922, 7221467, 7224118, 7226696, 7229224, 7231835, 7234448, 7237074, 7239661, 7242248, 7244831, 7247438, 7250010, 7252624, 7255179, 7257777, 7260342, 7262872, 7265456, 7267970, 7270545, 7273095, 7275708, 7278251, 7280851, 7283410, 7285994, 7288560, 7291115, 7293745, 7296316, 7298848, 7301442, 7304018, 7306655, 7309180, 7311705, 7314293, 7316887, 7319531, 7322112, 7324659, 7327260, 7329881, 7332442, 7335022, 7337604, 7340210, 7342739, 7345280, 7347817, 7350378, 7352945, 7355504, 7358025, 7360615, 7363210, 7365832, 7368429, 7371013, 7373605, 7376145, 7378732, 7381276, 7383811, 7386365, 7388933, 7391502, 7394032, 7396642, 7399245, 7401866, 7404457, 7406982, 7409538, 7412102, 7414691, 7417288, 7419884, 7422441, 7424989, 7427522, 7430101, 7432639, 7435216, 7437740, 7440294, 7442912, 7445516, 7448114, 7450684, 7453261, 7455841, 7458445, 7461027, 7463635, 7466198, 7468787, 7471320, 7473930, 7476552, 7479118, 7481641, 7484264, 7486781, 7489342, 7491952, 7494521, 7497063, 7499688, 7502254, 7504815, 7507392, 7509988, 7512553, 7515087, 7517707, 7520308, 7522824, 7525392, 7527945, 7530543, 7533105, 7535700, 7538260, 7540804, 7543418, 7545943, 7548535, 7551130, 7553729, 7556313, 7558844, 7561435, 7563980, 7566505, 7569080, 7571641, 7574170, 7576783, 7579338, 7581897, 7584422, 7587022, 7589577, 7592151, 7594705, 7597276, 7599794, 7602390, 7604973, 7607619, 7610137, 7612748, 7615269, 7617858, 7620416, 7622960, 7625549, 7628196, 7630753, 7633277, 7635834, 7638354, 7640910, 7643496, 7646121, 7648660, 7651279, 7653833, 7656431, 7659011, 7661580, 7664134, 7666612, 7669193, 7671776, 7674356, 7676915, 7679488, 7682031, 7684595, 7687146, 7689731, 7692293, 7694861, 7697419, 7700031, 7702574, 7705205, 7707783, 7710348, 7712918, 7715474, 7718028, 7720597, 7723207, 7725778, 7728305, 7730889, 7733442, 7736038, 7738641, 7741178, 7743670, 7746199, 7748766, 7751407, 7753967, 7756540, 7759095, 7761686, 7764213, 7766793, 7769379, 7771905, 7774461, 7777035, 7779545, 7782119, 7784671, 7787226, 7789834, 7792385, 7795028, 7797627, 7800194, 7802758, 7805346, 7807903, 7810459, 7813000, 7815577, 7818155, 7820761, 7823285, 7825842, 7828445, 7830988, 7833550, 7836167, 7838714, 7841312, 7843890, 7846422, 7848885, 7851434, 7854000, 7856583, 7859172, 7861776, 7864364, 7866909, 7869478, 7872018, 7874591, 7877131, 7879768, 7882314, 7884851, 7887428, 7890024, 7892632, 7895233, 7897844, 7900429, 7902975, 7905546, 7908066, 7910582, 7913125, 7915728, 7918312, 7920913, 7923470, 7926037, 7928634, 7931211, 7933766, 7936281, 7938828, 7941378, 7943902, 7946432, 7949032, 7951602, 7954217, 7956760, 7959316, 7961868, 7964451, 7967003, 7969567, 7972124, 7974694, 7977293, 7979866, 7982413, 7985018, 7987569, 7990128, 7992722, 7995266, 7997861, 8000394, 8002935, 8005473, 8008047, 8010615, 8013200, 8015753, 8018323, 8020862, 8023413, 8025983, 8028499, 8031030, 8033583, 8036158, 8038758, 8041400, 8043966, 8046482, 8049029, 8051591, 8054132, 8056748, 8059305, 8061849, 8064377, 8066944, 8069508, 8072033, 8074668, 8077206, 8079782, 8082323, 8084914, 8087510, 8090092, 8092568, 8095135, 8097678, 8100189, 8102726, 8105256, 8107767, 8110337, 8112936, 8115467, 8118011, 8120631, 8123161, 8125719};
const int sz  =100000;
const int maxn = 18000;
int sqr[maxn];
bool check(int x){
    int j=(int)sqrt(x)+1;
    for(int i=2; sqr[i]<=x; i++){
        if(x%i==0) return 0;
    }
    for(int i=1; sqr[i]<x; i++){
        for(;sqr[i]+sqr[j]>x;j--);
        if(sqr[i]+sqr[j]==x) return 1;
    }
    return 0;
}
int f(int x){
    int sum = t[x/sz];
    for(int i=(x/sz)*sz+1; i<=x; i++){
        sum+=check(i);
    }
    return sum;
}
int main(){
    for(int i=1; i<maxn; i++) sqr[i]=i*i;
    int l, r;
    scanf("%d%d", &l,&r);
    printf("%d\n", f(r)-f(l-1));
    return 0;
}