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: ['6921', 'a', 'U', '2821', '2111', 'h', '3937', '3697', 'd', '6309', 'q', '7961', '5287', '5375', '2721', '4523', 'V', '8633', 'c', '7643']
Example Output: 67939

Example Input: ['4241', 'E', '1807', '2877', '5125', '7625', 'S', '401', '5081', 'u', 'R', 'F']
Example Output: 27157

Example Input: ['T', '3469', 'R', 'p', 'Y', 'h', 'F', '8571', 'b', '4999', 'b', '3365', '6667', 'f']
Example Output:
27071