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: ['2573', '2195', '9929', 'H', '8877', 't', '9345', '669', 't', 'W', 'C', 'D', 'h', '7145', '5841', '1555', '6363', 'M', 'T', '9799', '4549', 'Y', '3555', 'i', 'n', '5773', '5075', 'X', '6889', 'l']

2573, 2195, 9929, 8, 8877, 20, 9345, 669, 20, 23, 3, 4, 8, 7145, 5841, 1555, 6363, 13, 20, 9799, 4549, 25, 3555, 9, 14, 5773, 5075, 24, 6889, 12