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: ['8821', '7221']

Answer: 16042


Question: ['O', '6337', 'j', '6009', 'z']

Answer: 12346


Question: ['9551', 'B', '1757', 'z', 'g', '525', '4847', 'q', '4901']

Answer:
21581