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: ['O', '3983', 'a', '1499', 'N', '3585', 'i', 'i', '2827', 'I', '3343', '7165', 'I', 'k', '3243', 'd', '1991', 'w', '5115', 'e']

15, 3983, 1, 1499, 14, 3585, 9, 9, 2827, 9, 3343, 7165, 9, 11, 3243, 4, 1991, 23, 5115, 5