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', 'j', 'W', '6881', '1909', '393', '1021', '1039', '5559']

4, 10, 23, 6881, 1909, 393, 1021, 1039, 5559