#include <iostream>
#include <iomanip>

using namespace std;

unsigned long Factorial(unsigned int n);


int main() {
    int i;

    for(i =0; i < 24; i++) {
       cout << setw(3) << i << "! = " << setw(20) << Factorial(i) << endl;
    }

    return 0;
}

unsigned long Factorial(unsigned int n){
    if (n <= 1) {
       return 1ul; 
    }

    return static_cast<unsigned long>(n) * Factorial(n-1);
}