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', '9899', '6309', 'G', 's', 'K', '819', 'K', '8883', 'j', 'i', 'v', '3815', '559', '2607', '5715', '5477', 't', 'D', '7569']

9, 9899, 6309, 7, 19, 11, 819, 11, 8883, 10, 9, 22, 3815, 559, 2607, 5715, 5477, 20, 4, 7569