#!/usr/bin/python2
# -*- coding: utf-8 -*-
# †
from math import factorial as fact

n = int(raw_input())

if n >= 50:
    print '0' * 12
else:
    res = fact(n)
    if res < 10 ** 12:
        print res
    else:
        res %= 10 ** 12
        print '{:012d}'.format(res)