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: ['t', 'x', '5629', 'k', '2003', 'v', '541', 'l', 'v', '7983', '677', '6173', 'z', 'J', 's', 'u', '2187', 'Y']
Example Output: 25193

Example Input: ['7669', '3367', 'A', 'Z', '6173', '4391', 'f', 'S', '9657', '2631']
Example Output: 33888

Example Input: ['r', 'M', 'L']
Example Output:
0