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: ['9143', '1959', '6777', 'e', 'Z', '1669', '5673', '939', 'p', '2971', '6885', '5107', '1585', '5957']

9143, 1959, 6777, 5, 26, 1669, 5673, 939, 16, 2971, 6885, 5107, 1585, 5957