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: ['8737', '9645', 'f', '7951', 'b', 'z', 'L', 'q', '5453', '6839', 'm', 'O', '9505', '2625', 'F', '2869', '7219', '7477', 't', '5613', 'z', 'L', 'M', '6639', '1499', 'S', 'Y', '9845', '4971', 'Y', '3159', '9289', 'M', 'H', '2999', '5491', '9585', 'P']

8737, 9645, 6, 7951, 2, 26, 12, 17, 5453, 6839, 13, 15, 9505, 2625, 6, 2869, 7219, 7477, 20, 5613, 26, 12, 13, 6639, 1499, 19, 25, 9845, 4971, 25, 3159, 9289, 13, 8, 2999, 5491, 9585, 16