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: ['m', '9515', '9971', '6297', 'd', 'w', '8689', 'p', 'L', '8137', '1015', '2655', 'e', '7365', 'T', '2301', '1629', 'B', '2043', 'I', 'C', 'k', 'o', '6137', '2557', '2701', '67', '6519', '4549', '6023', '9551', 'E', 's', '5571', '8815', '6511', 'r', 'a', '597']

13, 9515, 9971, 6297, 4, 23, 8689, 16, 12, 8137, 1015, 2655, 5, 7365, 20, 2301, 1629, 2, 2043, 9, 3, 11, 15, 6137, 2557, 2701, 67, 6519, 4549, 6023, 9551, 5, 19, 5571, 8815, 6511, 18, 1, 597