// Evalute the factorial of a number 

#include <iostream>
using std::cout;
using std::cin;
using std::endl;

int main()
{
  cout << " Give me an integer: ";
  int n;
  cin >> n;

  unsigned long fatt = 1;
  for (int i = 1; i <= n; i++)
    fatt = fatt * i;

  cout << n << "! = " << fatt << endl;

  return 0;
}