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', '6881', '759', '6693', 'i', 'c', '5921', 'z', 'w', '3775', '9997', 'e', '775']

15, 6881, 759, 6693, 9, 3, 5921, 26, 23, 3775, 9997, 5, 775