#include <iostream>

using lint = long long;

constexpr lint MOD = 1e12;

void solve() {
    lint n;
    std::cin >> n;

    lint ans = 1;
    for (lint i = 1; i <= n; ++i) {
        (ans *= i) %= MOD;
        if (ans == 0) break;
    }

    std::cout << ans << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}