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: ['H', 'X', '3679', 'i', 'P', '5717', '917', 'R', 'l', 'i', 't', 'O', '2921', '1315', 'D', 'G', '7031', 'h', 'u']

8, 24, 3679, 9, 16, 5717, 917, 18, 12, 9, 20, 15, 2921, 1315, 4, 7, 7031, 8, 21