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', '6021', 'C', 'P', 't', 'b', '915', '8343', '4223', '4289', 'A', '1081', 'a', '7729', 'n', '7989', 'f', 'n', '6229', '7477', '4317', '9753', 't', 'G', '2857', '1903', 't', '3581', '3373', '5115', '3057', '1025', '2457', '8493', '2419', 'h', 'r', 'k']

12, 6021, 3, 16, 20, 2, 915, 8343, 4223, 4289, 1, 1081, 1, 7729, 14, 7989, 6, 14, 6229, 7477, 4317, 9753, 20, 7, 2857, 1903, 20, 3581, 3373, 5115, 3057, 1025, 2457, 8493, 2419, 8, 18, 11