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: ['2787', 'z', '9351', '3339']
Example Output: 15477

Example Input: ['6321', 'M', 'd', '3673']
Example Output: 9994

Example Input: ['D', 'c', '4895', '4035', '1471', '2953', '4317', '9165']
Example Output:
26836