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: ['5545', '7973', 'M', 'y', '8231', 'D', '7831', '91', '5517', 'd', 'E', 'Y', 'S', 'c', '8775', '4131', '1279', 'b', 'M']

5545, 7973, 13, 25, 8231, 4, 7831, 91, 5517, 4, 5, 25, 19, 3, 8775, 4131, 1279, 2, 13