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: ['z', '447', '9781', 'R', '6083', 'u', '9229', 'Z', 'F', '2437', '9677', 'n', 'G', '6763', '5883', 'B', '9563', '4575']
Example Output: 64438

Example Input: ['O', '6337', 'j', '6009', 'z']
Example Output: 12346

Example Input: ['D', 'P', 'y', '4891', '1539', 'J', '5737']
Example Output:
12167