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: ['c', 'W', '9815', 'X', 'q', '8309', '7153', 'G', '7877', '6843', 'E', '7631', '4251', '9299', 'y']

3, 23, 9815, 24, 17, 8309, 7153, 7, 7877, 6843, 5, 7631, 4251, 9299, 25