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: ['Q', '6383', 'P', '8455', '3881', '5821', 'e', 'v', '1421', 'Q', '6377', '3157', '6407', 'q']
Example Output: 41902

Example Input: ['5199', 'h', 'T', 'T', 'l', '1661', 'p']
Example Output: 6860

Example Input: ['U', '1049', '3777', 'V', '1503', '3653', '7785', '4113', 'P', 'C', 'j', 'O']
Example Output:
21880