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:
['j', 'f', '3831', 'B', 'D']

Ex Output:
3831


Ex Input:
['4701', 'b', 'i', 'B', 'z', '7837', 'W']

Ex Output:
12538


Ex Input:
['8529', '2657', '1599', 'b', '8187', '7005', '7481']

Ex Output:

35458