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:
['8739', 'K']

Ex Output:
8739


Ex Input:
['d', '7305', '8903', 'b', '7687', '6393', '6939']

Ex Output:
37227


Ex Input:
['y', '4901', '7933', '5889', '7379', '379', 'Q', 'n', '7721', '4519', 'Y', '3305', 'N']

Ex Output:

42026