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: ['d', '1947', '1083', 'M', '1771', '3375', '9353', 'U']

4, 1947, 1083, 13, 1771, 3375, 9353, 21