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: ['1395', '3605', '6001', 's', 'h', 'T', 'K', 'X', '9413', 'X', '5099', 'c', 'f', 't', 'S', 'f', '4651']
Example Output: 30164

Example Input: ['y', 'N', '1279', '4293', '4309', 'F', 'W', 'u', 'g', 'j', 'Z', '1875']
Example Output:
11756