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: ['D', '8743', 'J', '6103', 'O', 'v', '7871', '9771', '4029']

4, 8743, 10, 6103, 15, 22, 7871, 9771, 4029