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: ['x', '9895', 'r', 'H', 'C']
Example Output: 9895

Example Input: ['2787', '6085', '6989']
Example Output: 15861

Example Input: ['Y', 'z', 'V']
Example Output:
0