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: ['7973', 'J', '9035', 'H', '4051', '2661', 's', 'z', '8225', 'M', '4153']
Example Output: 36098

Example Input: ['y', 'F', '135', '7359', '8579', '6809', '3979', 'H', 'm', '5059', '373', 'Y']
Example Output: 32293

Example Input: ['8981', '8189', 'x', 's', 'N', 'j']
Example Output:
17170