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', 't', 'K', '2111', 'w', 'M', '9225', 'g', 'f', '7617', '3043', 's', 'U', 'b', '8079', '3727', '6713', '6953', '5635', '1675']