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.
['d', 'c', '967', 'p', '8913', 'h', '4843', 'y', '2875', '1927', 'J', 'b', 'n', '9549', 'A', '4499', '5401', 'R']