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: ['i', '1191', '9111', 'i', 'S', '3177', '2915', 'e', 'p', '6959', 'O', '8031', 't', '263', '2153', 'Q']

9, 1191, 9111, 9, 19, 3177, 2915, 5, 16, 6959, 15, 8031, 20, 263, 2153, 17