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: ['u', '8121', 'P', 'l', 'Z', '3657', 'b', 'X', '8619', '1771', '2333', 'J', '7309', 'Q']

21, 8121, 16, 12, 26, 3657, 2, 24, 8619, 1771, 2333, 10, 7309, 17