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', 'v', '8287', '3449', '4903', 'j', '2975', 'u', '6673', 'f', '8085', 'i']

15, 22, 8287, 3449, 4903, 10, 2975, 21, 6673, 6, 8085, 9