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: ['833', 'V', '2521', 'Z', 'R', '2985', '6987', '2747', '4853']

833, 22, 2521, 26, 18, 2985, 6987, 2747, 4853