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: ['9651', 'b', '1549', '6447', 'x', '3367', '9047', '4215', 'X', 'n', '6137', '6067', 'U', '9785', 'P', '4561']

9651, 2, 1549, 6447, 24, 3367, 9047, 4215, 24, 14, 6137, 6067, 21, 9785, 16, 4561