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: ['3379', 'O', '6943', 'j', '9349', 'u', '7405', '167', '8405', 'Y', '3717', '9737', 'u', 'C', '5839', '1251', 'W']

3379, 15, 6943, 10, 9349, 21, 7405, 167, 8405, 25, 3717, 9737, 21, 3, 5839, 1251, 23