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: ['5217', '2293', 'X', '3187', '3787', '9731', '495', 'f', 'S', 'H', '1721', 'b', 'V', 'j', 'd', 'Y', '6769', 'a']

5217, 2293, 24, 3187, 3787, 9731, 495, 6, 19, 8, 1721, 2, 22, 10, 4, 25, 6769, 1