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: ['N', '1337', 'C', 'T', '863', 'j', '2369', 'P', 'A', 'x', '5725', '2333', 'Q', '9149', 'Q', '8529', 'N']
Example Output: 30305

Example Input: ['7959', '1345', '4605', '6453', 'Q']
Example Output: 20362

Example Input: ['F', '4605', 'x', '9299', 'F', '2723', '6215', '9115', 'N', '7621', '4139', '455', 'H', 'T', '9499']
Example Output:
53671