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: ['4139', 'J', 'v', '1713', '1485', '2951', '8977', 'l', 'J', '5597', '1359', 'L', 'Q', 'J']

4139, 10, 22, 1713, 1485, 2951, 8977, 12, 10, 5597, 1359, 12, 17, 10