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: ['6617', 'P', 'I', '2901', '1779', '2479', '2715', '3857', 'U', '1367', '9271', 'e', 'N', '7309', 'h', 'a', 'I', 'b', 'z', 'k', 'C', '4063', '2367', 'D', 'f', 'S', 'X', 'A', 'z', 'l', 'c', 'D']

6617, 16, 9, 2901, 1779, 2479, 2715, 3857, 21, 1367, 9271, 5, 14, 7309, 8, 1, 9, 2, 26, 11, 3, 4063, 2367, 4, 6, 19, 24, 1, 26, 12, 3, 4