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.

Example Input: ['c', 'r', 'R', 'a', '6915', 'C', '3651', 'j', 'L', '9761', '2923', 'Z', 'e', '833', 'W', '1867', 'G', 'H', 'T']
Example Output: 25950

Example Input: ['2729', 'W', 'i', '9073', '343', 'j', '2329', '9159', '4825']
Example Output: 28458

Example Input: ['c', '7415', '6253', '4477', 't', '9449', '7733', '2325', 'Z', '5413', 'q', 'm', 'R', '8619', '7289', '857', '7273', '7425']
Example Output:
74528