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: ['57', '9977', '2657', 'p', '9573', '7745', '4755', 'U']
Example Output: 34764

Example Input: ['6161', 'p', '2839', 'c', '5905', '1729', 'j', '5901', '3013', 'e']
Example Output: 25548

Example Input: ['o', 'L', 'z', '5207', 'v', 'p', 'J', 'V', '8389']
Example Output:
13596