题解 | 1=N

import sys
import math

n = 0
max_in = 0
ans = 0
for line in sys.stdin:
    a = line.split()
    n = int(a[0])
    max_in = int(math.sqrt(n))

for k in range(2, max_in):
    if (n % k == 0):
        num = 0
        while (n % k == 0):
            num += 1
            n /= k
        ans += num * k

if (n > 1):
    ans += n
print(int(ans))