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: ['9571', '5725', '3813', '9247', 'T', 'a', '49', 't', 'G', 'm', '9841', '99', '9121', 'B', 'z', 'r', 'R', 'y', '1803', '5973', 'o']

9571, 5725, 3813, 9247, 20, 1, 49, 20, 7, 13, 9841, 99, 9121, 2, 26, 18, 18, 25, 1803, 5973, 15