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: ['I', '1379', '7895', 'i', 'p', '4259', '7461', 'q', 'u']

9, 1379, 7895, 9, 16, 4259, 7461, 17, 21