Find Leap Year in c++

This program will tell you whether a given year is a leap year or not.

#include<iostream>
using namespace std;

 int  main()
 {
  int n;
  cout<<"Enter a year:";
  cin>>n;
  if(n%400==0)
 cout<<"\nNot a leap year.";
  else if(n%100==0)
   cout<<"\nNot a leap year.";
  else if(n%4==0)
   cout<<"\nIt's a leap year.";
  else
   cout<<"It's not a leap year.";
  system("pause");
  return 0;
 }

Output: Enter a year:2012 It's a leap year.