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: ['2689', '3557', '6111', 'R', '9941', 'b', '7697', 'G', '6481', '8869', 'G', '9139', 'p', 'q', 'R', 'G', '1913', 's', 'Z', 'r', 'B', '9947', '1427', '4139', '1653', '473', '9739', '3771', 'i', '3901', 'p']

2689, 3557, 6111, 18, 9941, 2, 7697, 7, 6481, 8869, 7, 9139, 16, 17, 18, 7, 1913, 19, 26, 18, 2, 9947, 1427, 4139, 1653, 473, 9739, 3771, 9, 3901, 16