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: ['u', '8109', '391', 'H', 'A', 'P', '3909', '7475', 'y', '3967', '7031', '6689', 'y', 'k', '3157', '2893', '4707', 'Q']

21, 8109, 391, 8, 1, 16, 3909, 7475, 25, 3967, 7031, 6689, 25, 11, 3157, 2893, 4707, 17