Read an integer value representing a year. Determines if the year is a leap year. Prompts the user to enter another year or quit.

A year is a leap year if −

1. It is evenly divisible by 100
2. If it is divisible by 100, then it should also be divisible by 400
3. Except this, all other years evenly divisible by 4 are leap years.

sample run:
Enter a year (0 to quit): 2024
2024 is a leap year

Enter a year (0 to quit): 1997
1997 is not a leap year

Enter a year (0 to quit):