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: ['6031', '4787', 't', '6297', 'O', '4103', 'U', '5553', 'n', 'U', '2273', 'L', 'U', '3997', '8311', 'P', '9347', 'N', 'c', 'g', '643', '1199', '7733', '1145', 'Z', '8535', '9289', 'l', 'z', '3965', 'F', 'b']

6031, 4787, 20, 6297, 15, 4103, 21, 5553, 14, 21, 2273, 12, 21, 3997, 8311, 16, 9347, 14, 3, 7, 643, 1199, 7733, 1145, 26, 8535, 9289, 12, 26, 3965, 6, 2