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', '7359', 'D', '2363', 'b', '3359', 'i', 'g', '7687', 'N', 'f', 'D', 'm', 't', '9553', 'N', 'V', '7657', '6589', 'q']