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: ['R', 'v', '2893', 'B', '4339', 'b', '8375', 'w', 'x', 'B', '2423', 'D']

18, 22, 2893, 2, 4339, 2, 8375, 23, 24, 2, 2423, 4