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: ['5851', '8883', '7577', '951', '8947', 'X', 'u', '8959', '9171', '7785', '1727', '5397', '3431', 'b', '2857', 'n', 'H', '3759']

5851, 8883, 7577, 951, 8947, 24, 21, 8959, 9171, 7785, 1727, 5397, 3431, 2, 2857, 14, 8, 3759