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: ['s', 'N', '9599', 'f', '47', '2499', '8197', '6555', '1485', '6571', '8805', 'F', '1939', 'C', 's', 'X', 'e', 'T', 'M', 'u']

19, 14, 9599, 6, 47, 2499, 8197, 6555, 1485, 6571, 8805, 6, 1939, 3, 19, 24, 5, 20, 13, 21