#include 
#include 
#include 
using namespace std;


int factorial(int number) {
    if(number == 1) {
        return 1;
    }
    return factorial(number - 1) * number;
}
int main() {
    cout << factorial(5) << endl;
    return 0;
}
// factorial(5) = factorial(4) * 5 = 24 * 5 = 120
// factorial(4) = factorial(3) * 4 = 6 * 4 = 24
// factorial(3) = factorial(2) * 3 = 2 * 3 = 6
// factorial(2) = factorial(1) * 2 = 1 * 2 = 2
// factorial(1) = 1