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: ['s', '9751', 'J', 'O', '3057', '1533', 'i', 'K', '8447', '8771', '775', '5511', '3439', '3663', '73', 'c', '4613', 'y']

19, 9751, 10, 15, 3057, 1533, 9, 11, 8447, 8771, 775, 5511, 3439, 3663, 73, 3, 4613, 25