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', '9707', '5367', '533', 'C', 'g', '5039', '4489', '8129', '5419', 'w', 'P', '4025', '641', 'B', '7423', 'e', 'Q', '4235', '9235', 'y', 'r']

21, 9707, 5367, 533, 3, 7, 5039, 4489, 8129, 5419, 23, 16, 4025, 641, 2, 7423, 5, 17, 4235, 9235, 25, 18