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: ['6577', 'Q', '6865', '7671', 'N']
Example Output: 21113

Example Input: ['1965', '8127', 'x', '4981', '8077', 'O', '467', '701', 'V', 'm', 'y', '5989', '123', 't', '4019', 'j', '1827', '8799']
Example Output: 45075

Example Input: ['2793', 'c', '7233', 'a', 'c', '841', 'I', '2299', '9755', '3673', '2823', '5651', '2207', 'n', 's', 'w', 'z', '4055', 'c']
Example Output:
41330