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: ['7435', '4139', '3521', '3265', 'r', '3825', 'W', '9003', '4043', 'x', '2429']

7435, 4139, 3521, 3265, 18, 3825, 23, 9003, 4043, 24, 2429