#include <iostream>
#include <cstdlib>
using namespace std;

int factorial(int i);

int main()
{

	//Output the product of the ints from 1 to 10 inclusive.
	cout << factorial(10) << "\n";

	return EXIT_SUCCESS;
}

//Return the product of the ints from 1 to n inclusive.

int factorial(int n)
{
	if (n < 0) {
		cerr << "Can't take the factorial of a negative number.\n";
		exit(EXIT_FAILURE);
	}

	if (n > 1) {  //If the job is not finished yet,
		//Do only the last multiplication here;
		//call the function to do the remaining multiplications.
		return n * factorial(n - 1);
	}

	//Arrive here if the job is so small that it is already finished;
	//no multiplications are necessary.
	return 1;
}