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: ['6471', 'R', 'X', '2521', '6065', 'F', 'm', '8271', 'z']

6471, 18, 24, 2521, 6065, 6, 13, 8271, 26