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: ['3351', '6445', 'Y', '8455', 'V', 'z', 'a', 'V', 'S', '8551', '4101', 'q', '8743', '5999', '7155', '3825', '2241', '9957']
Example Output: 68823

Example Input: ['6629', 'o', 'e', '497', '4865', '8733', '5733', '7337', 'N']
Example Output: 33794

Example Input: ['m', '2141', 'a', '4109']
Example Output:
6250