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.

['5877', '217', '1531', '3153', 'r', '5987', '8561', '2249', 'p', 'D', '8307', '3895', 'v', 'R', 'Y', 'N', '5319', '6971', '6515', '8633', '853', '4675', 'd', 'P']
5877, 217, 1531, 3153, 18, 5987, 8561, 2249, 16, 4, 8307, 3895, 22, 18, 25, 14, 5319, 6971, 6515, 8633, 853, 4675, 4, 16