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: ['a', 'f', '2185', 'N', '6381', '6429', '7499', 'd', '757', 'k', 'k', 'b', 'N', '2697', 'A', '8037']
Example Output: 33985

Example Input: ['q', 'N', 'y', '7859', 'u', '2861', '4151', 'Q', 'x']
Example Output: 14871

Example Input: ['l', '3793', 'M', '2933', '5139']
Example Output:
11865