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:
['a', 'f', '2185', 'N', '6381', '6429', '7499', 'd', '757', 'k', 'k', 'b', 'N', '2697', 'A', '8037']

Ex Output:
33985


Ex Input:
['r', '3139', 'C', 'L', '7335', 'v', '9861', 'F']

Ex Output:
20335


Ex Input:
['9837', '2627', '5307', '4037', 'a']

Ex Output:

21808