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.
['9805', '3827', '1481', 'U', '6209', 'D', '5413', 'Z', 'h', 'K', '1737', '3127', 'B', 'b', '1567', 'w', 'f', 'Z', 'm']