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

Example Input: ['Z', '4157', '5185', 'U', 'i', '1115', 'A', '7427', '3313', 'S']
Example Output: 21197

Example Input: ['4315', '8583', '8369', '6529', '8779', 'v', 'Q', 'f', 'M', '3907', '2717', 'J', '437', '9505', 'R', 'O', 'H']
Example Output:
53141