当L=11时就会失效，不知道什么原因，请大佬指点

import math
def demo(n):
    if n == 1:
        return False
    for i in range(2,int(math.sqrt(n)+1)):
        if n % i == 0:
            return False
    return True

L = int(input())  # 上限
i = 2; times = 0; begin = 0
while begin < L:  #大前提是累加的值小于或等于L
    if demo(i):  # 判断质数
        print(i)
        times += 1
        begin += i
    i += 1
print(times)