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:
['8755', 'A', '2893', '6703']

Ex Output:
18351


Ex Input:
['7473', 'W', 'H', '9893', '1857', '6523', '1333', 'a']

Ex Output:

27079