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: ['7179', 'b', '8721', '9751', '5849', 's', '3769', '9277', 'O', '5129', 'S', 'P', 'Z', '8449', '6635', '6587', '489', 'Q', '853', 'W', '5547', 'Z']

7179, 2, 8721, 9751, 5849, 19, 3769, 9277, 15, 5129, 19, 16, 26, 8449, 6635, 6587, 489, 17, 853, 23, 5547, 26