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: ['R', 'X', '5545', '7437', 'x', 'A', '4871', 'z', 'X', 'X', 'p', 's', 'X', 'J', 'l', '1347', '9217', 's', '5605', '4389', '8877', '4201', '7487', '8837', '4807', 'U', 'B', 'K', 'q', '4257', 'i', '9055', '2621', 'b', 'D']

18, 24, 5545, 7437, 24, 1, 4871, 26, 24, 24, 16, 19, 24, 10, 12, 1347, 9217, 19, 5605, 4389, 8877, 4201, 7487, 8837, 4807, 21, 2, 11, 17, 4257, 9, 9055, 2621, 2, 4