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.
['8339', 'H', 's', 'C', '4361', 'D', 'C', '2291', '5695', 'T', 'h', 'E', 'R', 'i', 'g', '1941', 'y', '3363']