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: ['6731', 'f', '4561', '5601', 'i']

Answer: 16893


Question: ['p', 'z', 'U', '105', 'Z', 'P']

Answer:
105