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: ['6629', 'o', 'e', '497', '4865', '8733', '5733', '7337', 'N']
Example Output: 33794

Example Input: ['Y', '8169', '9067']
Example Output: 17236

Example Input: ['5349', 'm', 'R', '8807', '1865', '3243', 'd', 'b']
Example Output:
19264