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: ['D', 'P', '9951', '2897', 'V', 'C', 'B', 'H', 'c', 'h', '2843', 'a']

Answer: 15691


Question: ['B', 's']

Answer: 0


Question: ['9791', '7813', '9083', '7263']

Answer:
33950