yeh

 #include <iostream>

using namespace std;

int main ()

{ typedef unsigned int us;

  us n; us f = 1;

  cout << "Enter a non-negative integer : ";

  cin >> n;

  for (us i=1 ; i<+ n; i++)

  f* _ i;

  cout << n <<"! = " << f << end1; 

  return 0; }