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.
['G', '6383', 'T', '4691', 'k', 'B', 'A', '1511', 's', '1095', '119', '4293', '3155', '6513', '8337', 'T', 'M', 'F', 'i', '5111']