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: ['o', 'q', '4591', 'E', '5325', 'W', 'O', 'p', 'L', '4161', '15', '6653', '3473', 'K', '2863']

15, 17, 4591, 5, 5325, 23, 15, 16, 12, 4161, 15, 6653, 3473, 11, 2863