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: ['2839', '9791', '5721', '5165', 'H', 'T', 'u', 'I', 'Z', '3187', 'i', '925', '1561', 'q', '3665', 'S', '7719', 'E', '1893', '2607', '9457', 'c', '5617', '2279', '3469', 'O', '3921', '9471', '2237', 'J', 'J', '3849', '39', 'd', '3545', '8691']

2839, 9791, 5721, 5165, 8, 20, 21, 9, 26, 3187, 9, 925, 1561, 17, 3665, 19, 7719, 5, 1893, 2607, 9457, 3, 5617, 2279, 3469, 15, 3921, 9471, 2237, 10, 10, 3849, 39, 4, 3545, 8691