#include <iostream>
using namespace std;

long long n;

int main() {
	cin >> n;
	
	long long ans = 1;
	for (int i = 1; i <= n; i++) {
		ans *= i;
		ans %= 1000000000000;
		if (ans == 0) { break; }
	}
	cout << ans << endl;
	
	return 0;
}