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: ['H', 'F', '4971', 'F', '4269', '6909', 'B', 'h', '4135', '1127', '5873']

8, 6, 4971, 6, 4269, 6909, 2, 8, 4135, 1127, 5873