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: ['6645', 'k', '4879', 'N', '113', 'L', 'x', '8365', 'v', 'A']
Example Output: 20002

Example Input: ['8683', 'p', '47', '8983', 'g', 'u']
Example Output: 17713

Example Input: ['2561', '7381', 'L', 'T', 'r', 's']
Example Output:
9942