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: ['7857', '7145', '9701', '8919', 'w', '2393', 'E', '7209', 'a', 'C']

7857, 7145, 9701, 8919, 23, 2393, 5, 7209, 1, 3