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: ['u', 'B', '5563', '9539', '9371', 'K', '7955', '97', 'l', 'S', '5499', 'J', '7645', 'a', '4101', '4947', 'y', 'x', '1283', 'G', '5547', 'c']

21, 2, 5563, 9539, 9371, 11, 7955, 97, 12, 19, 5499, 10, 7645, 1, 4101, 4947, 25, 24, 1283, 7, 5547, 3