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: ['8555', 'i', 'k', 'S', '2087', '3173', 'L', 'c', '6565', '5925', '7023', '723', '4561', '1783', '4133', '9889', '3921', '1277', '3951', 'B']

8555, 9, 11, 19, 2087, 3173, 12, 3, 6565, 5925, 7023, 723, 4561, 1783, 4133, 9889, 3921, 1277, 3951, 2