Write a program Greatest Common Divisor that finds the greatest common divisor (gcd) of two integers using Euclid’s algorithm, which is an iterative computation based on the following observation: if...

Write a program Greatest Common Divisor that finds the greatest common divisor (gcd) of two integers using Euclid’s algorithm, which is an iterative computation based on the following observation: if x is greater than y, then if y divides x, the gcd of x and y is y; otherwise, the gcd of x and y is the same as the gcd of x % y and y.