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: ['4601', '6021', '3005', 'I', 'f', '4631', 'Q', 'd', '8041', 'D', '8067', '7383', '757', 't', 'd', 'n', '2275', 'p', 'm', '6021']
Example Output: 50802

Example Input: ['2787', 'z', '9351', '3339']
Example Output: 15477

Example Input: ['8373', '1639', '6827', '9353', '8545', 'N']
Example Output:
34737