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: ['o', '5749', 'H', '971', 'l', 'W', 'L', '6563', 'm', 'h', '281', '2847', '3615', 'f', '7137', 'Z', '3475', '6683', '7989', 'G', 'D', '861', 'b', 'A', '5991', '7935', '9073', '8535', '4117', 'C', '8811', 'D', 'h', '5905']

15, 5749, 8, 971, 12, 23, 12, 6563, 13, 8, 281, 2847, 3615, 6, 7137, 26, 3475, 6683, 7989, 7, 4, 861, 2, 1, 5991, 7935, 9073, 8535, 4117, 3, 8811, 4, 8, 5905