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: ['4579', 'C', 'z', 'n', '4995', 'J', '1973', '885', '665', '2831', 'u', '5109', '1877', 'a', 's', 'Q', '3731', '3477', 'X', 'y', '9877']

4579, 3, 26, 14, 4995, 10, 1973, 885, 665, 2831, 21, 5109, 1877, 1, 19, 17, 3731, 3477, 24, 25, 9877