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: ['7831', 'x', '6165', '5103', '3499', '6909', 'J', '2661', 'G', 'm', '4263', 'S', '8951', 'O', '7227', 'C']

7831, 24, 6165, 5103, 3499, 6909, 10, 2661, 7, 13, 4263, 19, 8951, 15, 7227, 3