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: ['2773', 'U', 'D', '5695', 'n', 'G', 'O', 'O', 'l', 'G', '2685', '7875', '469', 'h', 'U', 'c', 't', '4403', '6883']

2773, 21, 4, 5695, 14, 7, 15, 15, 12, 7, 2685, 7875, 469, 8, 21, 3, 20, 4403, 6883