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: ['D', '1693', 'f', 'B', 'o', '3947', '8667', 'f', '6721', '4191', '79']
Example Output: 25298

Example Input: ['1671', 'H', '9271']
Example Output: 10942

Example Input: ['2413', '5479', '6259', 'R', '3239', 'M', 'm', 'l', 'A', '3477', 'U', '4455', 't', 'q', 'W', 'o', 'w', '5801']
Example Output:
31123