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: ['4305', 'U', '6931', 'o', 'C', '7129', 'Q', 'J', '1941', '1057', 'B', 'o', 'c', '7109', '3103', 'a', 'r', '6423', 'v', '6485', 'u']

4305, 21, 6931, 15, 3, 7129, 17, 10, 1941, 1057, 2, 15, 3, 7109, 3103, 1, 18, 6423, 22, 6485, 21