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: ['I', 'a', '3031', '1227', '4635', 'S', '5313', 'k', 'A', '5131', 'C']

9, 1, 3031, 1227, 4635, 19, 5313, 11, 1, 5131, 3