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: ['6913', 'Y', 'f', 'j', 'H', '7215', '4003', 'd', 'n', '2407', '6483', 'F', '5569', 'e', '7707', 'r', '617', 'P', 's', '7021', '8603', '4543', 'i', 'i', '3415', 'B', '8073']

6913, 25, 6, 10, 8, 7215, 4003, 4, 14, 2407, 6483, 6, 5569, 5, 7707, 18, 617, 16, 19, 7021, 8603, 4543, 9, 9, 3415, 2, 8073