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: ['857', 'A', '2749', 's', 'j', 'N', 'y', '1609', '199', '9527', '2483', '9169', 'e', '9755', 'U', 'z', 'y', 'N', '3463', '2405', 'z']

857, 1, 2749, 19, 10, 14, 25, 1609, 199, 9527, 2483, 9169, 5, 9755, 21, 26, 25, 14, 3463, 2405, 26