#include<cstdio>

 using namespace std;

 typedef long long ll;

 const int N = ;

 const int mod = 1e8;

 ll a[N] = {};

 int n;

 int main(){

     int i, j, c, cnt;

     scanf("%d", &n);

     cnt = ;

     for(j = ; j <= n; ++j){

         for(c = i = ; i <cnt; ++i){

             a[i] = a[i] * j + c;

             c = a[i] / mod;

             a[i] %= mod;

         }

         if(c > ){

             a[i] = c;

             cnt++;

         }

     }

     printf("%lld", a[--cnt]);

     while(cnt){

         printf("%08lld", a[--cnt]);

     }

     return ;

 }