#include <iostream>
#include <iomanip>
#include <string>

using lint = long long;

constexpr lint MOD = 1e12;

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

    lint ans = 1;
    bool over = false;
    for (lint i = 1; i <= n; ++i) {
        ans *= i;
        if (ans > MOD) over = true;
        ans %= MOD;

        if (ans == 0) break;
    }

    if (over) {
        std::cout << std::setw(12) << std::setfill('0');
    }
    std::cout << ans << std::endl;
}

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

    solve();

    return 0;
}