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: ['K', '4403', 'a', '3881', '4139', 'w', '1861', 'G']

Answer: 14284


Question: ['X', 'f', 'p', 'R', 'N']

Answer: 0


Question: ['K', 'r', '4195', 'g', 'h', '1583', 'P', 'q', '8457', '3221', 'o', 'N', '9727', 'm', '3967', 'l', 'B']

Answer:
31150