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.

['r', '3537', 'T', '3611', 'k', '4983', 'h', '4317', '8727', 'E', '6471', '8465', 'f', '5429', 'T', '2169', '2171', 'P', '6941', 'D']
56821

['6669', 'n', 't', 'N', 'x', '8153', 'W', 'v', 'B', '3181', 'y', 'e', '3491']
21494

['7279', 'E', 'a', '6361', '2585']

16225