#include <bits/stdc++.h>
using namespace std;

int main() {
    int64_t N;
    cin >> N;
    if (N >= 50) {
        cout << setfill('0') << right << setw(12) << 0 << endl;
    } else {
        const int64_t MOD = 1'000'000'000'000;
        int64_t ans = 1, over = false;
        for (int i = 1; i <= N; ++i) {
            ans *= i;
            if (ans > MOD) {
                over = true;
                ans %= MOD;
            }
        }
        if (over) cout << setfill('0') << right << setw(12) << ans << endl;
        else cout << ans << endl;
    }
    return 0;
}