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: ['2087', '8171', 'c', 'd', 'a', '5621', 'n']

Answer: 15879


Question: ['1305', '1673', 'w']

Answer: 2978


Question: ['R', 'q', 'r', '7823', '2995', 'z', '7843', 'B', 'd', '8165', '7589', 'c', '2621', 'p', 'u', 'a', 'c']

Answer:
37036