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: ['6921', 'a', 'U', '2821', '2111', 'h', '3937', '3697', 'd', '6309', 'q', '7961', '5287', '5375', '2721', '4523', 'V', '8633', 'c', '7643']

SOLUTION: 67939

PROBLEM: ['t', '7015', '2239', 'I', 'F', 'E', '1363', '9615', '6179', '2539', 'z', '8745', '1319', '4715', '9071', 'K', '3707', '6149', 'd']

SOLUTION: 62656

PROBLEM: ['p', 'f', 'V', 'h', '7899', '3387', '497']

SOLUTION:
11783