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: ['4515', '5147', 'k', 'J', '9649', 'T', 'S', '8729', 'm', '9141', '7771', '2765', '9589', 'R', '7927', 'd', '5569', '1039', '6889', 'E', 'I', 'z', 'O', '6015']

4515, 5147, 11, 10, 9649, 20, 19, 8729, 13, 9141, 7771, 2765, 9589, 18, 7927, 4, 5569, 1039, 6889, 5, 9, 26, 15, 6015