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: ['Y', '8169', '9067']

Answer: 17236


Question: ['m', '3481']

Answer: 3481


Question: ['2049', '2057', 'p', '5255', '4741', 'G', '4473', '8695', 'u', '2919', 'D', 'J', '8225', 'v', 'R', '1979']

Answer:
40393