#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <map>


typedef long long ll;
#define fi first
#define se second

using namespace std;

ll N;
ll num;
ll ans;

#define mod  1000000000000
            //123456789012
int main(){
  
  cin>>N;
  
  int k = 12;
  
  ans = 1;
  int jdg = 1;
  int i;
  
  if( N < 50 ){
    while( N ){
      ans *= N;
      if( ans >= mod ){
        jdg = 0;
      }
      ans %= mod;
      N--;
    }
  }
  
  else{
    jdg = 0;
    ans = 0;
    k = 11;
  }
  
  if( jdg ) cout<<ans<<endl;
  
  else{
    ll d = ans;
    while( d ){
      k--;
      d /= 10;
    }
    for( i = 0; i < k; i++ ){
      cout<<'0';
    }
    cout<<ans<<endl;
  }
  
  return 0;
}