TASK DEFINITION: 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.
PROBLEM: ['29', 'N', '5061', '7191', 'z', '8367']

SOLUTION: 20648

PROBLEM: ['n', 'G', '5059', '8343', '8673', 'P', 'N', '5485', '2279', '6121', 'i', 'U', '7277', '8701', 'A', 'b', 'Z', 'R', '6371', 'G']

SOLUTION: 58309

PROBLEM: ['Q', 'h', '6525', '6449', 'b', 'K', 'a', '5067', 'D', 'U', 'a', 'a', '8277', '505', '4929']

SOLUTION:
31752