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: ['n', '2787', '645', '7459', '3671', 'J', '1545', 'b', 'H', 's', 'k', '2125', 'B', '1091', '5387', 'T', 'r', '7005', '8459']

14, 2787, 645, 7459, 3671, 10, 1545, 2, 8, 19, 11, 2125, 2, 1091, 5387, 20, 18, 7005, 8459