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', 'O', '3095', 'k', '9199', '1409', '4567', '5345', '4685', '6661', '7659', 'K', '4731', '2157', 'l', 'Y', '8991', '2757', '8333', '8371', '4305']

21, 15, 3095, 11, 9199, 1409, 4567, 5345, 4685, 6661, 7659, 11, 4731, 2157, 12, 25, 8991, 2757, 8333, 8371, 4305