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: ['1539', 'e', 'L', 'H', 'y', 'J', '8555', '3245', '5785', 'n', 'r']

1539, 5, 12, 8, 25, 10, 8555, 3245, 5785, 14, 18