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: ['T', 'c', '4145', 'I', '8787', '9305', '7963', '7957', 'u', 'G', 'F', 'l', '8315', '2539', '4401', 'J', '4235', 'O', '7283', 'g', 'k', 'G']

20, 3, 4145, 9, 8787, 9305, 7963, 7957, 21, 7, 6, 12, 8315, 2539, 4401, 10, 4235, 15, 7283, 7, 11, 7