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: ['887', '8133', 'X', '2253', '8461', 'I', '5425', 'Z', 'z', 'r']
Example Output: 25159

Example Input: ['G', 'Z', '4819', '9763', '9987']
Example Output: 24569

Example Input: ['I', '33', 'x', 'P', '7581', 's', '1409', 'O', '9799', '4617']
Example Output:
23439