#include <iostream.h>

long factorial(int);   // function prototype

int main()
{
  int n;
  long result;

  cout << "Enter a number: ";
  cin >> n;
  result = factorial(n);
  cout << "\nThe factorial of " << n << " is " << result << endl;

  return 0;
}

long factorial(int n)
{
  if (n == 1)
    return n;
  else
    return n * factorial(n-1);
}