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', 'e', 'R', '4427', '3401', '3065', 'I', '2781', '6829', '5261']
25764

['A', '771', 'Q', 'b', '9929', '4991', 'q', '9863', '4363', '5721', 'C', '991', 'j', 'r', 'Q', 'B', 'K']
36629

['6577', 'Q', '6865', '7671', 'N']

21113