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: ['A', '4751', 'O', '9217', '3087', '6821', 'N', 'N', '9239', '7225', 'U', 'x', 'i', 'v', '9625', 'J', '3507', '8435', '8279', '4875', '8971', 'S', '8077']

1, 4751, 15, 9217, 3087, 6821, 14, 14, 9239, 7225, 21, 24, 9, 22, 9625, 10, 3507, 8435, 8279, 4875, 8971, 19, 8077