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: ['7147', '1657', '1217', '3681', '6209', 'm', '4273', '8243', 'G', 'a', '3589', '8461', 'o', 'b', 'M', 'e', 'p', '5841', 'y', 'J', 'S']

7147, 1657, 1217, 3681, 6209, 13, 4273, 8243, 7, 1, 3589, 8461, 15, 2, 13, 5, 16, 5841, 25, 10, 19