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: ['6347', '5495', '169', '9503', 'H', '571', '6105', 'X', 'r', 'e', '7369', 'a', 'd', '6999']

Answer: 42558


Question: ['6165', 'x', 'u', 'n', 'V', 'B', '4039', 'l', '991', 'x', '335', '9011', 'K', '8725', 'a', '6291', 'j']

Answer: 35557


Question: ['d', '4553']

Answer:
4553