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: ['U', '9593', '2079', '5959', 'T', '5849', 'w', 'b', '9743', '6689', 'k', 'J']

SOLUTION: 39912

PROBLEM: ['A', '9785', '1739', 'x', '2389', 'O', 'J', '1407', '9067', 'x', '9747', '2485', '4631', '6021', '4077', '2779', 'V', '2449', '7401']

SOLUTION: 63977

PROBLEM: ['y', 'E', 'E', '3243', '9661', 'j', '7835', 'H', '4901', '9963', 'y', '3199', '3511']

SOLUTION:
42313