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: ['L', '671', '3589', '7983', 't', '7951', 'E', '8235', '7595', 'a', 'K', '3429', '8285']

12, 671, 3589, 7983, 20, 7951, 5, 8235, 7595, 1, 11, 3429, 8285