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: ['2653', '6177', 'M', 'O', 't', '337', 'T', '2877', 'u', 'P', 'h', '91', '2015', '8437', 'b', '8117']

2653, 6177, 13, 15, 20, 337, 20, 2877, 21, 16, 8, 91, 2015, 8437, 2, 8117