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', '7305', '8903', 'b', '7687', '6393', '6939']
Example Output: 37227

Example Input: ['K', 'p', '97', 'R', '2999', 'u', '7307', '6033', '6431', 'm', 'T']
Example Output: 22867

Example Input: ['n', '219', 'z', '645', 'r', 'n', 'p', 'j', 'V', 'e']
Example Output:
864