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.
['7581', '8627', 'g', '3453', 'n', 'q', '8973', 'F', '8731', '4551', '9479', 'E', '4135', '2243', 'S', '1031', '6067', '4367', 'e']