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', '9043', '6405', '159', '3203', 'p', '2403', '2247', '2583', '7865', 'f', '9541', '2551', 'C', 'n', '1983', '9885', '7429', 'Z']

4, 9043, 6405, 159, 3203, 16, 2403, 2247, 2583, 7865, 6, 9541, 2551, 3, 14, 1983, 9885, 7429, 26