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: ['n', 'F', 'n', 'H', '1083', 'o', 'b', 'k', '2863', 'c', '1311', 'R', 'c', '5315', '8573', '1985', '637']

14, 6, 14, 8, 1083, 15, 2, 11, 2863, 3, 1311, 18, 3, 5315, 8573, 1985, 637