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: ['E', 'j', 'H', 'L', 'I', '9657', 'a', '8897', 'B', '5503', 'e', '2357', '8387', '5373', 'W', '3919', '2921']

5, 10, 8, 12, 9, 9657, 1, 8897, 2, 5503, 5, 2357, 8387, 5373, 23, 3919, 2921