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: ['829', '6713', '5923', 'P', 'J', '2909', 'X', '3409', '8797', '6919', '5213', 'z', '8843', 'D', 'R', 'o']

829, 6713, 5923, 16, 10, 2909, 24, 3409, 8797, 6919, 5213, 26, 8843, 4, 18, 15