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: ['6781', 'B', 'A', '185', '6579', 'H', '6185', 'C', '721', '2719', '2861', '2405', '1085', 'D']

6781, 2, 1, 185, 6579, 8, 6185, 3, 721, 2719, 2861, 2405, 1085, 4