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

Ex Output:
20002


Ex Input:
['P', '237', 'X', '8893', '7931', 'F', '8359', 'S', '6931', '6953', 'r']

Ex Output:
39304


Ex Input:
['n', 'p']

Ex Output:

0