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: ['Y', '3243', '7759', '9275', 'e', '2875', 'F', 'w', 'E', '1555', 'r', 'X', 'S']

25, 3243, 7759, 9275, 5, 2875, 6, 23, 5, 1555, 18, 24, 19