#include <iostream>
using namespace std;

long double factorial(unsigned n) {
	if (n == 0) return 1;
	long double result = n;
	while (n --> 1) {
		result *= n;
	}
	return result;
}

int main() {
	unsigned n;
	cin >> n;
	while (n >= 0) {
		cout << n << "! = " << factorial(n) << endl;
		cin >> n;
	}
}