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: ['1003', '4317', '7717', '7821', 'B', '8287', '8923', 'a', '4251']

1003, 4317, 7717, 7821, 2, 8287, 8923, 1, 4251