Please include explanations beside every code. Thank you.

10. Greatest Common Divisor Write a function, gcd(n,m), that returns the greatest common divisor of the numbers n and m. The greatest common divisor of two numbers is largest number that evenly di- vides both numbers. You may assume that n and m are positive integers greater than 11. In the following number, the four adjacent digits that give the largest product are: 9 x 9 X 8 X 9= 5832. 5100474821663704844031998900088952434506585412275886 Write a function max_product that takes as input a base 10 number s (represented as a string), and outputs the product of the twelve adjacent digits that have the greatest product