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', '2651', 'B', 'N', 's', '8825', 'E', '7981', '1539', 'L', 'h', '9021', '2657', '6439', '1863', 'Y', 'f']

4, 2651, 2, 14, 19, 8825, 5, 7981, 1539, 12, 8, 9021, 2657, 6439, 1863, 25, 6