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: ['g', '5301']

SOLUTION: 5301

PROBLEM: ['w', '8035', 'J', '2671', '7509', '1573', '6915', '8569', '345', 'T', 'P', 's', '1341', '7823', '8671', 'm', 'Q', 's', 'N']

SOLUTION: 53452

PROBLEM: ['D', '4275', 'R', '5939', 'r', '9373', 'X', 'W', 't', '1781']

SOLUTION:
21368