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', '9407', '1903', 'G', 'H', 'l', '7193', '3721', 'D', 'M', 'v', 'C', '91', '8137', '805', 'B', 'l', '5809', 'y', '6621', '4615', '5043', '2769', 'I', 'm']

14, 9407, 1903, 7, 8, 12, 7193, 3721, 4, 13, 22, 3, 91, 8137, 805, 2, 12, 5809, 25, 6621, 4615, 5043, 2769, 9, 13