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: ['6433', 'k', 'K', '9751', 'z', 'L', '5991', '7475', '1399', '3819', '879', 'Z', '6449', 'F', 'b', '237', '7327', 'f', '8867', '3405', 'M', 'K', 'z', '5661', '5469']

6433, 11, 11, 9751, 26, 12, 5991, 7475, 1399, 3819, 879, 26, 6449, 6, 2, 237, 7327, 6, 8867, 3405, 13, 11, 26, 5661, 5469