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: ['w', '2281', '8651', '2203', 'q', 'n', '4253']
Example Output: 17388

Example Input: ['2013', 'S', 's', '9353', 'b', 'u', '6687', '5429', '3545', '7269']
Example Output: 34296

Example Input: ['7313', 'w', 'k', '7113', '7763', 'f', '6293', 'k', 'M', 'x', '4761', 'U', 'V', '6753', 'a', '2411']
Example Output:
42407