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: ['b', 'M', 'p', '8875', '9779', '9267', 'P', '5469', 'Y', '2645', 'G', 'Y', 'u', '3641', '4519']

2, 13, 16, 8875, 9779, 9267, 16, 5469, 25, 2645, 7, 25, 21, 3641, 4519