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: ['29', 'N', '5061', '7191', 'z', '8367']
Example Output: 20648

Example Input: ['7755', '8383', 'y', 'k', '4869', '2809']
Example Output: 23816

Example Input: ['z', '2601', 'b', 'Z', 'H', 'p', 'p', 'N', 'l', 'o', 'N', 'Z', '3103', '4767', 'I', 'K', '2113']
Example Output:
12584