#include<iostream>

  using namespace std;

 int main()
  {
  int nfact=1, n;

  cout<<"Enter positive integer: ";
  cin>>n;
  for (n; n>1; n--)
  {
     nfact = nfact*n;
  }

cout <<"n!="<< nfact<<endl;
 system("pause") ;
 return 0;
 }