#include <iostream.h>

int getnum(void);
int factorial(int n);

int main()
{
  int value;

  cout << "Enter 0 to exit.\n";

  value = getnum();

  while (value != 0)
    {
      cout << "Factorial: " << factorial(value) << endl;

      value = getnum();
    }

  return 0;
}


int getnum(void)
{
  int num;

  cout << "Number: ";
  cin >> num;

  return num;
}


int factorial(int n)
{
  if (n <= 1)
    return 1;

  return n * factorial(n - 1);
}