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: ['z', '447', '9781', 'R', '6083', 'u', '9229', 'Z', 'F', '2437', '9677', 'n', 'G', '6763', '5883', 'B', '9563', '4575']
Example Output: 64438

Example Input: ['7465', 'G', '105', 'A', '3987', 'O', '7385', 'C', '8957']
Example Output: 27899

Example Input: ['c', '5941', 'k', 'N', '7763', '1293', '5867', 'B', '8917', 'H', 'W', '7813', '7525', '7439', '9537', '2909']
Example Output:
65004