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: ['g', 'l', 'W', '6707', '2541', 's', '281', 'B', 'X', 'U', '7745', '8343', '2737', '5431', 'W', '3515', 'i', '7715', '7909', 'B', '4919', '4593', 'a', '3127', 'n', '2465', 'r', 'O', 'D']

7, 12, 23, 6707, 2541, 19, 281, 2, 24, 21, 7745, 8343, 2737, 5431, 23, 3515, 9, 7715, 7909, 2, 4919, 4593, 1, 3127, 14, 2465, 18, 15, 4