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: ['4891', '8307', 'y', 'v', '4107', 'O', 'K', 'r', '9727', 'L', '6917', '9177', 'I', 'm', 'R', '6345', '9851']

4891, 8307, 25, 22, 4107, 15, 11, 18, 9727, 12, 6917, 9177, 9, 13, 18, 6345, 9851