求1000阶乘中最后0的个数

# -*- coding: utf-8 -*-
"""
Created on Tue Mar 22 18:10:46 2016
求1000阶乘中最后0的个数
@author: root
"""

def fun1():
    N = 1000
    ret = 0;
    for i in range(1,N+1,1):
        j=i;
        while j%5==0:
            ret=ret+1;
            j=j/5;
    print ret

def fun2():
    N = 1000
    ret = 0;
    while N:
        ret=ret+N/5;
        N=N/5;
    print ret