#include <iostream>
using namespace std;
#define ll long long
const ll MOD = 1e12;
int main() {
	cin.tie(0);ios::sync_with_stdio(false);
	ll N; cin >> N;
	ll ans = 1;
	for (ll i = 1; i <= N; i++) {
		(ans = ans * i) %= MOD;
	}
	cout << ans << endl;
}