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', 'A', 'A', '5729', '6717', '9171', '2245', '5017', 'T', '8013', '9991', 'o', 'n', 'e', 'n', 'G', 'G', '6581']

6, 1, 1, 5729, 6717, 9171, 2245, 5017, 20, 8013, 9991, 15, 14, 5, 14, 7, 7, 6581