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: ['s', 'g', 'Z', '8919', 'R']
Example Output: 8919

Example Input: ['3809', '9401', '63', '5705', 'u', '6275', 'k', 'l', '1171', '9365', 'L', 'O', '7431', '8567', 'h', '6135']
Example Output: 57922

Example Input: ['1281', '573', 'G', '8945', '9801', 'x', '6481', 'Y', '2359', '7759', '8209', '2875', '4869', '257', 'C', '1665', '7927', '7']
Example Output:
63008