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: ['7551', 'O', 's', 'D', '7865', '5827', 'h', '5401', 'l', 'h', 'w', 'l', '7695', '2997', '9895', '4681', '6097', '405', 'N', '5371', 'c', '8535', '2631', 'p', '7853', 'y']

7551, 15, 19, 4, 7865, 5827, 8, 5401, 12, 8, 23, 12, 7695, 2997, 9895, 4681, 6097, 405, 14, 5371, 3, 8535, 2631, 16, 7853, 25