题解 | 小红的“质数”寻找

import sys
import math

def iszhishu(n):
    if n < 2:
        return 0
    if n == 2:
        return 1
    for i in range(2,int(math.sqrt(n))+1):
        if n%i == 0:
            return 0
    return 1

while True:
    try:
        T = int(input())
        for i in range(T):
            x = int(input())
            if x <10:                    
                flag = 0
                for i in range(x,x*2+1):
                    s = str(i)
                    sumx = 0
                    for ss in s:
                        sumx += int(ss)
                    if iszhishu(sumx):
                        print(i)
                        flag = 1
                        break
                if flag == 0:
                    print(-1)
            else:
                ss = str(x)
                y = 0
                if ss[0] == '1':
                    if int(ss[1])<5:
                        y = 2*10**(len(ss)-1)
                    else:
                        y = 3*10**(len(ss)-1)
                elif ss[0] == '2':
                    y = 3*10**(len(ss)-1)
                elif ss[0] == '3' or ss[0] == '4':
                    y =5*10**(len(ss)-1)
                elif ss[0] == '5' or ss[0] == '6':
                    y =7*10**(len(ss)-1)
                else:
                    y =11*10**(len(ss)-1)
                print(y)
                


    except:
        break