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: ['e', 'i', 'R', 's', 'a', 'I', '9553', '5935', '5925', 'Q', '7921', 'e']

5, 9, 18, 19, 1, 9, 9553, 5935, 5925, 17, 7921, 5