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: ['L', '9997', '1225', 'Y', '4947', '7515', 'l', '3297', '2377', '7735', '4331', 'L', '6223', 'q', 'X', '8679', '673', '6397', '6247', 'W', '971', '3799', 't', 'v', 'r']

12, 9997, 1225, 25, 4947, 7515, 12, 3297, 2377, 7735, 4331, 12, 6223, 17, 24, 8679, 673, 6397, 6247, 23, 971, 3799, 20, 22, 18