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.

['643', '47', '7955', 'F', 'n', 'G', 'a', '9879', '107', '311', '1641', '6939', '5773', '3343', '1581', '2857', '471', '3521', '5463', 'H', '2533', 'Z', '8191', '9121', 'D', '507', '8889', 'P', 'c', '2569', 'T', '6797', '483']
643, 47, 7955, 6, 14, 7, 1, 9879, 107, 311, 1641, 6939, 5773, 3343, 1581, 2857, 471, 3521, 5463, 8, 2533, 26, 8191, 9121, 4, 507, 8889, 16, 3, 2569, 20, 6797, 483