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: ['7449', '837', '5877', '9421', '4929', 'X', 'm', 'Y', 'E', 'U', 'l', 'T', '5539', '6273', 't', 'K', 'x', 'b', 'z', '1637', '553', '4977', '6007', 'i', '7667', 'T', '9459', '5547', '2291']

7449, 837, 5877, 9421, 4929, 24, 13, 25, 5, 21, 12, 20, 5539, 6273, 20, 11, 24, 2, 26, 1637, 553, 4977, 6007, 9, 7667, 20, 9459, 5547, 2291