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: ['6907', 'O', 'y', '2643', '5619', '3883', '5019', '1901', '9051', 'd', 'm', 'i', '1387', 'X', 'd', '2285', 'x']

6907, 15, 25, 2643, 5619, 3883, 5019, 1901, 9051, 4, 13, 9, 1387, 24, 4, 2285, 24