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: ['7153', 'e', 'c', 'Y', 'y', '8887', '3409', '5891', '8715', 'T', 'X', '1671']

7153, 5, 3, 25, 25, 8887, 3409, 5891, 8715, 20, 24, 1671