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: ['4773', '1039', 'c', '721', '4777', '6299', 'e', 'W', 'v', 'R', '3547', '2471', 'W', 'H', '8755']

4773, 1039, 3, 721, 4777, 6299, 5, 23, 22, 18, 3547, 2471, 23, 8, 8755