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: ['8653', 'u', '7809', '737', '6333', 'B', 'J', '4869', 'N', '6111', 'I', '4083', 'A', 'V', '8255', 'O']

8653, 21, 7809, 737, 6333, 2, 10, 4869, 14, 6111, 9, 4083, 1, 22, 8255, 15