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: ['M', '1485', '997', 'T', '5431', 's', '8867', '1181', 'J', '5517', '7013', 'H', '4955', '5711', 's', '7125', 'f', '6029', 'a', '6285']

13, 1485, 997, 20, 5431, 19, 8867, 1181, 10, 5517, 7013, 8, 4955, 5711, 19, 7125, 6, 6029, 1, 6285