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: ['o', '9393', '6021', '5339', '8749', 'E', 'e', '8919', '8807', '709']

15, 9393, 6021, 5339, 8749, 5, 5, 8919, 8807, 709