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: ['s', 'c', 'N', 'Y', '7755', '8871', 'e', '8409', 'T', '7897', 'm', 'U', '1305']

19, 3, 14, 25, 7755, 8871, 5, 8409, 20, 7897, 13, 21, 1305