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: ['4675', 'c', '885', '7821', '2645', 'u', 'O', '8975', 'y', '3591', 'U', '1209', '2315', 'p', '6013', '4425', '9693', 'K', 'b', 'B', '4681', 'n', 'E', '2861', '5045', 'U', '815']

4675, 3, 885, 7821, 2645, 21, 15, 8975, 25, 3591, 21, 1209, 2315, 16, 6013, 4425, 9693, 11, 2, 2, 4681, 14, 5, 2861, 5045, 21, 815