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:
['7771', 'g']

Ex Output:
7771


Ex Input:
['6731', 'f', '4561', '5601', 'i']

Ex Output:
16893


Ex Input:
['R', 'V', 'B', 'z', '5805', 'B', 'B', 'j', '853', '8203', '2797', '5257', 'b', 'I', 'Z']

Ex Output:

22915