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

ll MOD = 1e12;
bool over = false;

ll fact(ll n) {
    ll memo;
    if (n == 1) return 1;
    else {
        memo = n * fact(n-1);
        if (memo > MOD) over = true;
        return memo % MOD;
    }
}

int getDigit(ll n) {
    return to_string(n).length();
}

int main(void) {
    ll N;
    cin >> N;
    ll ans = fact(N);
    if (!over) cout << ans << endl;
    else {
        for (int i=0; i<12 - getDigit(ans); i++) cout << 0;
        cout << ans << endl;
    }
    return 0;
}