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: ['J', 't', 'I', '1639', '3505', '5653', '9199', 'E', 'I', '8869', 'n', 'n', 'b', '997', 'b', '1721', '9585', 'q', 'l', 'h', 't', 'O', '9999', '4795', 't', '6909', '9365', 'n', '3931', 'J', 'q', '6007', 'Z', '8983', 'b']

10, 20, 9, 1639, 3505, 5653, 9199, 5, 9, 8869, 14, 14, 2, 997, 2, 1721, 9585, 17, 12, 8, 20, 15, 9999, 4795, 20, 6909, 9365, 14, 3931, 10, 17, 6007, 26, 8983, 2