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', '639', '8827', 'U', '8899', 'y', 's', '3459', 'q', 'V', '3225', 'f', '9719', '7423', '7825', '2539', '6215', 'r', '3509', '2687', '3823', 'l', 'O', '2551', '7007', 'd', '8129', '3001', '9081', '2437', 'D', 't', '8717', 'x']

13, 639, 8827, 21, 8899, 25, 19, 3459, 17, 22, 3225, 6, 9719, 7423, 7825, 2539, 6215, 18, 3509, 2687, 3823, 12, 15, 2551, 7007, 4, 8129, 3001, 9081, 2437, 4, 20, 8717, 24