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: ['L', 'I', '2593', 'F', 'q', '1509', 'c', 'r', '429', '2235', 'I', 'M', 'U', 'a']

12, 9, 2593, 6, 17, 1509, 3, 18, 429, 2235, 9, 13, 21, 1