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: ['S', 'u', '3049', 'Y', 'Y', '5393', '223', 'u', '9599', '8585', '89', '1231', '4951', '3377', 'h', '5333', '5163', '8327', 't']

19, 21, 3049, 25, 25, 5393, 223, 21, 9599, 8585, 89, 1231, 4951, 3377, 8, 5333, 5163, 8327, 20