A leap year in the Gregorian calendar system is a year that's divisible by 4 but not by 100, unless it is also divisible by 400. For example, 1896, 1904, and 2000 were leap years but 1900 was not. Write a function that takes in a year as input and prints whether it's a leap year (or not). In the program, ask the user to input a year and then call the function to determine whether the input year is a leap year or not. Display the result to the user.