#include <bits/stdc++.h>
using namespace std;
using ll = long long;

map<ll, ll> memo;

ll f(ll n){
  if(memo.find(n) != memo.end()) return memo[n];
  if(n<=1) return memo[n] = 1;
  else return memo[n] = (n*f(n-1))%1000000000000;
}

int main(){
  ll n; cin >> n;
  if(n<=50) cout << f(n) << endl;
  else cout << 0 << endl;
  return 0;
}