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: ['g', '7973', 'W', '2559', '713', '6405', 'L', 'f', 'x', 'f', '503', 'a', 'A', 'N', 'a']

7, 7973, 23, 2559, 713, 6405, 12, 6, 24, 6, 503, 1, 1, 14, 1