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: ['a', 'm', '3205', '1869', '1117', 'K', '5785']
Example Output: 11976

Example Input: ['x', 'd', '5121', 'I', '6737', '3789', '6167', 'C', '8947', 'k', '4715', '1885', 'H', 'B', '5685', 'S', '4615', 's', '7709']
Example Output: 55370

Example Input: ['b', '2697', 'D', '6029', 'p', '4401', '4777', 'h', 'x', 'P', '9669', 'L', '6593']
Example Output:
34166