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: ['u', '7487', '3795', 'u', 'U', 'F', '4579', 'p', 'l', '5165', '5527', 'a']

21, 7487, 3795, 21, 21, 6, 4579, 16, 12, 5165, 5527, 1