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: ['Z', '6245', 'N', '1403', 'b']
Example Output: 7648

Example Input: ['5715', 'r', 'R']
Example Output: 5715

Example Input: ['9261', 'h', '347', '4393', 'm', 'w', '941', 'R', 'Q', '7713', '4477']
Example Output:
27132