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:
['V', '8137', 'b', 'k', '2081', 'L', '9733', '7525', 'D', '2381', 'O']

Ex Output:
29857


Ex Input:
['k', 'a']

Ex Output:
0


Ex Input:
['7427', 'p', '8723', '4087', '1631', '9117', '6505']

Ex Output:

37490