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: ['N', '1337', 'C', 'T', '863', 'j', '2369', 'P', 'A', 'x', '5725', '2333', 'Q', '9149', 'Q', '8529', 'N']
Example Output: 30305

Example Input: ['6051', '5303', '1509', '2797', 'Z', '4777', '721', '8563', 'K', '63', '9115', 'd', '7305', '9743', '7409']
Example Output: 63356

Example Input: ['g', '7473', 't', '2957', '3753', 'Q', '1853', 'G', 'm']
Example Output:
16036