#include <iostream>

using namespace std;

int main()
{
    unsigned int n{0};
    unsigned int i{1};
    unsigned long long total{0};

    cout << "Enter a nonnegative integer: ";
    cin >> n;

    while ( i < n ){
            total = total * ( n - i );
            i++;
        }
        cout << "The factorial of this nonnegative integer is: " << total << endl;
}