In this task, you are given an input list A. You need to find all the elements of the list that are numbers and calculate their sum.
['H', '8117', 'D', 'I', '8213', 'y', '5051', '1627', '1099', 'y', '2469', 'h', '6517', '8807', '4047', '4597', '6531', 'j']