#include <iostream>
#include <iomanip>
#include <fstream>
#include <vector>
#include <string>

using namespace std;

void fact2(int n) {
    unsigned long long int MAXIMUM = 1000000000000;
    vector<unsigned long long int> result = { 1 };
    for (int i = 2; i <= n; i++) {
        unsigned long long int d = 0;
        for (int j = 0; j < result.size(); j++) {
            unsigned long long int p = result[j] * i + d;
            result[j] = p % MAXIMUM;
            d = p / MAXIMUM;
            /*cout << d << " d" << endl;
            cout << result.size() << " size" << endl;*/
        }
        /*cout << "end?" << endl;*/
        if (d > 0) {
            /*cout << d << " not end" << endl;*/
            result.push_back(d);
        }
        /*coutVector2(result);
        cout << endl;*/
    }
    ofstream myfile;
    myfile.open("output.txt");
    myfile << result[result.size() - 1];
    for (int i = result.size() - 2; i >= 0; i--) {
        myfile << setfill('0') << setw(12) << result[i];
    }
    myfile.close();
}

int main() {
    string INT;
    ifstream infile;
    infile.open("input.txt");
    getline(infile, INT);
    int n = stoi(INT);
    infile.close();
    fact2(n);
    return 0;
}