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: ['7501', 'c', 'n', '3551', 'U', '8239', 'L', '3149', '9399', 'a', '2763', '2461', 'p']

7501, 3, 14, 3551, 21, 8239, 12, 3149, 9399, 1, 2763, 2461, 16