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: ['135', 'a', 'X', '8067', '8447', '4009', '4221', 'o', 'A', 'x']
Example Output: 24879

Example Input: ['d', '6851', 'o', '5521', 'l', '3911', 'w', '1005', 'e', '3323', 'r', '7311', '4377']
Example Output: 32299

Example Input: ['579', '9839', 'z', '9557', '1657', '6319', 'm', 'K', 'F', 'L', 'k', 'q', 'r', '4703', '921', '7765', '9367', 'C']
Example Output:
50707