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: ['1875', '9833', 'i', '7493', 'J', 'P', 'z']

SOLUTION: 19201

PROBLEM: ['K', 'O', 'p', '1669', '8647', '3417', 'a', '8903', 'V', 'E', 'l', 'a', '5177', 'J', '6559', '5377', 'X', '9427']

SOLUTION: 49176

PROBLEM: ['6121', 'S', '8683', 'Y', '6107', 'B', '6193', '5555', '365', '945', '1439', '7257', 'g']

SOLUTION:
42665