Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['X', 'T', '4971', '4177', 'c', 'M', 'a', 'c', 'A', 'N', 'S', 'N', '4977', '9747', 'M', 'u']

24, 20, 4971, 4177, 3, 13, 1, 3, 1, 14, 19, 14, 4977, 9747, 13, 21