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: ['9521', 'Y', 'z', '6619', '775', 'I', '4053', '7507', '9377', 'M', 'R', 'w', 'L', '9675', '4219', '1271', '7883', '6171', '5607', 'I', '8537', 'u', '4699', '99', '2879', '4057', '4447', '2517', 'A']

9521, 25, 26, 6619, 775, 9, 4053, 7507, 9377, 13, 18, 23, 12, 9675, 4219, 1271, 7883, 6171, 5607, 9, 8537, 21, 4699, 99, 2879, 4057, 4447, 2517, 1