#include <iostream>
#include <string>

using namespace std;

int main() {
    const long long max = 1e12;
    long long answer = 1;
    long long n;
    cin >> n;
    for (long long i = 2; i <= n; i++) {
        answer *= i;
        answer %= max;
    }

    cout << answer << "\n";

    int a;
    cin >> a;

    return 0;
}