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:
['t', '7469', 'Y', 'N', '8137']

Ex Output:
15606


Ex Input:
['c', '4501', 'O']

Ex Output:
4501


Ex Input:
['F', 'X', 'Y', '8251', '1461']

Ex Output:

9712