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: ['M', '6273', '6875', '107', 'n', 'c', 'F', 'B', 'P']

13, 6273, 6875, 107, 14, 3, 6, 2, 16