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: ['D', 'G', '9895', '143', '37', 'S', '1539', 'x', 'a', 'x', 'B', 'i', '9719', '839']

SOLUTION: 22172

PROBLEM: ['7379', 'I', '2031', '8419', 'w', 'b', '9827', 'X', 'Y', 't', '3789', 'B', 'c', '6599', 'F', '6169', 'V']

SOLUTION: 44213

PROBLEM: ['k', '1373', 'E', '4543', 'E', 'k', 'U', 'P', 'b', '8083', '5631', '4395', '4265', '9963', 'F', '8893', '639', 'p']

SOLUTION:
47785