/* -*- coding: utf-8 -*-
 *
 * 500.cc: No.500 階乗電卓 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

typedef long long ll;
const ll MOD = 1000000000000;

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  ll n;
  cin >> n;

  bool of = false;
  ll f = 1;
  for (ll i = 1; f > 0 && i <= n; i++) {
    f *= i;
    if (f >= MOD) of = true;
    f %= MOD;
  }

  if (of) printf("%012lld\n", f);
  else printf("%lld\n", f);
  return 0;
}