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: ['Y', '8457', '9543', '4723', '9697', '5839', 'f', 'o', '4315', '3993', '1061', 'f', 'z', '6947', 'M', '4757', '8109', '2725', '4517', 'U', '3375', '5905', '1429', '4683', '4393', 'W', '3757', 'J', '3473', '3709']

25, 8457, 9543, 4723, 9697, 5839, 6, 15, 4315, 3993, 1061, 6, 26, 6947, 13, 4757, 8109, 2725, 4517, 21, 3375, 5905, 1429, 4683, 4393, 23, 3757, 10, 3473, 3709