#include <iostream>
using namespace std;
int main()
{
    int year;
    cout << "Enter a year: ";
    cin >> year;
    if(year%4 == 0)
    {
        if( year%100 == 0)
        {
            // year is divisible by 400 is a leap year
            if ( year%400 == 0)
                cout << d << "is a leap year.";
            else
                cout << d << "is not a leap year.";
        }
        else
            cout << d << "is a leap year.";
    }
    else
        cout << d << "is not a leap year.";
    
    return 0;
}