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.
--------
Question: ['2787', 'z', '9351', '3339']

Answer: 15477


Question: ['P', '6161', 'k', '5925', 'h', 'G', 'n']

Answer: 12086


Question: ['i', 'O', '7881', 'Y', 's', 'G', '7445', '6671', '5415', 'B', '2129', '9493', '3039', 'r', 'F', 'b', '2499', 'N']

Answer:
44572