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.
['249', 'G', '6451', 'V', '3249', '6179', 'R', '3925', 'w', '1493', 'U', '8809', 'T', '1649', 'h', 'L', '9289', '2117', 'e', '5769']