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: ['F', '8903', 'd', 'F', '3943', 'p', 'O', '495', 'l', 'z', '4621', 'D', 'K', 'h', 'F', '427', 'C', 'L', 'y', '4157', 'U', 'C', 'T', '9077', 'H', 'N', '263']

6, 8903, 4, 6, 3943, 16, 15, 495, 12, 26, 4621, 4, 11, 8, 6, 427, 3, 12, 25, 4157, 21, 3, 20, 9077, 8, 14, 263