#include <iostream.h>

int product(int n)
{
  cout << "n (product): " << n << endl;
  
  int total;
  while (n > 0) {
    cout << "n,total (loop top): " << n << " " << total << endl;

    n = n-1;
    total = total*n;
    
    cout << "n,total (loop bottom): " << n << " " << total << endl;
  }
  return total;
}

int main()
{
  int n;
  cin >> n;
  cout << product(n) << endl; /* print 1*...*n */
}