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: ['L', 'q', '3211', '5395', 'R', '9715', '1681', '8237', '6471', '4459', 'p', 'Q', 'n', 'V', '351', 'O']

12, 17, 3211, 5395, 18, 9715, 1681, 8237, 6471, 4459, 16, 17, 14, 22, 351, 15