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', 'n', '4835', 'S', '4397', '3647', 'Z', '3681', 'a', '9865', '4083', '2377', 'S', '4371', 't', 'i', '8315', 'X', '9683', '4723', 'M', '2985', 'J', 'r', '619', 'N']

13, 14, 4835, 19, 4397, 3647, 26, 3681, 1, 9865, 4083, 2377, 19, 4371, 20, 9, 8315, 24, 9683, 4723, 13, 2985, 10, 18, 619, 14