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: ['U', 't', 'i', '2995', '4685', 'W', '9559', '2613', '5241', '657', '3815', '9903', 'W', 'a', '2815', 'y']

21, 20, 9, 2995, 4685, 23, 9559, 2613, 5241, 657, 3815, 9903, 23, 1, 2815, 25