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:
['2787', 'z', '9351', '3339']

Ex Output:
15477


Ex Input:
['6645', 'k', '4879', 'N', '113', 'L', 'x', '8365', 'v', 'A']

Ex Output:
20002


Ex Input:
['4023', 'C', 'D', 'n', 'Q']

Ex Output:

4023