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: ['9427', 'O', '739', 'O', 'U', '7757', '4249', 'i', '5119', 'b', 'I', 'M', '7427', 's', '2447', 'E', 'X', 'T', '1027', 'G', 'g', 'd', 'L']

9427, 15, 739, 15, 21, 7757, 4249, 9, 5119, 2, 9, 13, 7427, 19, 2447, 5, 24, 20, 1027, 7, 7, 4, 12