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:
['Q', '8317', '8989']

Ex Output:
17306


Ex Input:
['3839', 'D', '4741', 'L']

Ex Output:
8580


Ex Input:
['7781', 'B', '5797', 'N', 'V', 'I', 'a', '8977', '3705', 'b', '3579']

Ex Output:

29839