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: ['1819', '8923', '4347', '7805', 'M', 'o', 'P', 'h', 'i', '997', '2173', 'D', '5493', '9731', '3591']

1819, 8923, 4347, 7805, 13, 15, 16, 8, 9, 997, 2173, 4, 5493, 9731, 3591