def get_quad(n, p):
    return 0
        
def sieve():
    n = 10000001
    p = [1] * n
    p[0] = p[1] = 0
    
    for i in range(int(n ** 0.5)):
        if p[i]:
            for j in range(2 * i, len(p), i):
                p[j] = 0
    return p
import sys
f = sys.stdin

prime = sieve()
while True:
    ni = int(f.readline())
    if ni == 0:
        break