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:
['p', '4689']

Ex Output:
4689


Ex Input:
['W', 'H', 'k', 'L', '2425']

Ex Output:
2425


Ex Input:
['O', 'y', '2887']

Ex Output:

2887