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

Ex Output:
39304


Ex Input:
['1203', '6179', '9835']

Ex Output:
17217


Ex Input:
['N', 'V', 't', 'X', 't', 'M']

Ex Output:

0