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: ['5893', '3337', '9087', '2785', '499', '3599', 'U', '6053']

5893, 3337, 9087, 2785, 499, 3599, 21, 6053