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: ['2977', '4895', 'e', '7599', 's', '8699', 'c', '1531', 'P', 'S', 'n', '9599', '6343', '2839', '6217']

2977, 4895, 5, 7599, 19, 8699, 3, 1531, 16, 19, 14, 9599, 6343, 2839, 6217