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

ll n;

int main(){
  cin>>n;
  ll sum=1;
  for(int i=1;i<=n;i++){
    sum=((sum%1000000000000)*(i%1000000000000))%1000000000000;
  }
  cout<<sum<<endl;
  return 0;
}