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: ['P', '1643', '1071', '5715', '2927', '3057', 'B', 'D', '9937', '5191', '1893']

16, 1643, 1071, 5715, 2927, 3057, 2, 4, 9937, 5191, 1893