#include<bits/stdc++.h>
using namespace std;
int n;
const int N = 1e5;
int a[N],x,lenc = 1;
int main()
{
	cin>>n;
	a[1] = 1;
	for(int i = 1;i <= n;i++){
		x = 0;
		for(int j = 0;j <= lenc;j++){
		 	a[j] = a[j] * i + x;
		 	x = a[j] / 10;
		 	a[j] %= 10;
		 	if(x > 0 && j >= lenc) lenc++;
		}
	}
	for(int i = lenc;i >= 1;i--) cout<<a[i];
	return 0;
}