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', '6085', '6989']

Ex Output:
15861


Ex Input:
['W', 'c', '7971', 'J', 'o']

Ex Output:
7971


Ex Input:
['2457', 'H', '8201', '4309', '6593', '2305', 'L']

Ex Output:

23865