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: ['1507', 'Z', 'Q', '2369', 'u', 'y', '2589', 'D', 'P', '1967', '719', 'U', '9541', '3185', 'Y', 'x', '887', 'C', '2561', '4659', '145', 'B', '4153', 'e', '8831', 'I', '9299', '2833', '8413']

1507, 26, 17, 2369, 21, 25, 2589, 4, 16, 1967, 719, 21, 9541, 3185, 25, 24, 887, 3, 2561, 4659, 145, 2, 4153, 5, 8831, 9, 9299, 2833, 8413