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: ['4969', '2921', 'F', '9125', '7721', '1213', '1271', '6045', '5527', '2121', '9787', 'D', 'A', '3809', '4013', '4259', 'o', 'E', 'z', '5881', 'D', 'C', 'l']

4969, 2921, 6, 9125, 7721, 1213, 1271, 6045, 5527, 2121, 9787, 4, 1, 3809, 4013, 4259, 15, 5, 26, 5881, 4, 3, 12