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', 'D', 'B', '549', 'e', '3', 'y', 'e', '3171', 'F', 'u', '5779', '7201']

12, 4, 2, 549, 5, 3, 25, 5, 3171, 6, 21, 5779, 7201