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: ['9419', 't', '9383', 'o', 'Y', 'T', '5949', 's', '1957', 'O', 'w', '3573', 'W', 's', '9431', 'c', '6711']

9419, 20, 9383, 15, 25, 20, 5949, 19, 1957, 15, 23, 3573, 23, 19, 9431, 3, 6711