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: ['C', 'D', '3859', '9651', 'x', 'q', '8967', '7801', 'e', '5609', 'E', 'U', 'q', '6323', 'W', 'B', 'M', '5033', 'D', 'u', 'i']

3, 4, 3859, 9651, 24, 17, 8967, 7801, 5, 5609, 5, 21, 17, 6323, 23, 2, 13, 5033, 4, 21, 9