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: ['O', '9911', 'b', '5201', 'g', '6991', 'p']

15, 9911, 2, 5201, 7, 6991, 16