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: ['507', 'P', '9697', 'u', '5057']

SOLUTION: 15261

PROBLEM: ['L', 'i', '9225', 'w', '5365', '8077', '2733', 'W', '8493', 'B']

SOLUTION: 33893

PROBLEM: ['U', '2273', 'P', 'J', '9807', 'A', 'W', '3827', 'H', 'd', 'k', '1193']

SOLUTION:
17100