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.

Ex Input:
['291', 'R', 'N', '983', '2879', 'C', '3797', '4837', '793', '5489', 'k', '535', 'L', '3605', 's', '3701', 'U', '4399', '2489', '4739']

Ex Output:
38537


Ex Input:
['8529', '2657', '1599', 'b', '8187', '7005', '7481']

Ex Output:
35458


Ex Input:
['3039', 'g', '8897', 'h', '9293', '3161', '19']

Ex Output:

24409