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: ['8601', '5709', 'l', 'B', 'b', 'U', '3987', 'C', '8939', 'D', '4611', '6499', '8487', '5715', 'F', '6203', 'Q', 'a', 'P', '5471', '8029', '1645', '2241', 'T', '8565', 'd', 'C', 'P', '7015', 'C', 'c', 'P']

8601, 5709, 12, 2, 2, 21, 3987, 3, 8939, 4, 4611, 6499, 8487, 5715, 6, 6203, 17, 1, 16, 5471, 8029, 1645, 2241, 20, 8565, 4, 3, 16, 7015, 3, 3, 16