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: ['q', 'z', '427', '2359', 'i', 'l', '7849', '4987', 'M', '3373', '6419', 'a', 'v', 'r', 'a', '8251', '5391', '5145', '3577', 'S', '9851']

17, 26, 427, 2359, 9, 12, 7849, 4987, 13, 3373, 6419, 1, 22, 18, 1, 8251, 5391, 5145, 3577, 19, 9851