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', 'A', '1425', '8595', 'J', '6251', '2809', '2067', '7809', 'D', 'O', 'U', 'O', '9943', 'i', 'q', '3297', '8507', '681', '3229', '1791', '6637', 'M']

20, 1, 1425, 8595, 10, 6251, 2809, 2067, 7809, 4, 15, 21, 15, 9943, 9, 17, 3297, 8507, 681, 3229, 1791, 6637, 13