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 βˆ’

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):