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: ['8815', '9479', 'N', '2509', 'W', 'o']

8815, 9479, 14, 2509, 23, 15