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: ['5917', '8987', '3021', 'L', 'f', '1989', '8577', '3361', '8767', 'x', 'w', '8905', '7341', 'H']

5917, 8987, 3021, 12, 6, 1989, 8577, 3361, 8767, 24, 23, 8905, 7341, 8