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:
['B', 'K', '9399', 't', '5541', 'w', '1939', '7841', 'q']

Ex Output:
24720


Ex Input:
['m', '3481']

Ex Output:
3481


Ex Input:
['y', 'Q', '7731', '8217', '3129', '6785', '2801', '5101', '4777', '9631', '539', 't', '1887']

Ex Output:

50598