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: ['U', 'x', 'q', '9755', '21', 'O', '9281', 'F']

21, 24, 17, 9755, 21, 15, 9281, 6