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: ['4949', '2459', 'n', 'f', 'n', 'v', '8421', '1519', '4859', 'c', '9923', '2829', 'K', '4937', 'W', 'R']
Example Output: 39896

Example Input: ['b', 's', 'v', '4757', '9063', 'I', '8397', '7975', 'Q']
Example Output: 30192

Example Input: ['8559', 'A', 'I', 'k', '8077', 'M', 'Q', 'N', 'E', '171', 'P', '6193', '2493', '1467']
Example Output:
26960