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: ['H', '189', '4109', 'a', 'm', 'c', 'r', 'l', 'U', 'I', '9931', '9167', '7587']

8, 189, 4109, 1, 13, 3, 18, 12, 21, 9, 9931, 9167, 7587