#include<bits/stdc++.h>
#define MOD 1000000000000
#define rep(i,n)for(int i=0;i<(n);i++)
using namespace std;
typedef long long ll;

int main() {
	ll n; scanf("%lld", &n);
	ll a = 1;
	for (int i = 1; i <= n; i++) {
		(a *= i) %= MOD;
		if (a == 0)break;
	}
	cout << a << endl;
}