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', '479', 'u', '3489', 'o', '9589', '7153', '7649', '123', 'a', 'A', '3951', '847', 'N', 'R', '947', '9243', 'G', 'a']

Answer: 43470


Question: ['u', 'e', 'P', 'D', '255', '2573', 'E', 'P', 's', '3725', '3391', 'I', '5323', '885']

Answer: 16152


Question: ['687', 'r', 'M', '7663', 'h', 'C', 'Z', '4891', '2227', 'D', '3411', 'T']

Answer:
18879