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: ['W', 'c', '7971', 'J', 'o']

SOLUTION: 7971

PROBLEM: ['9989', 'B', 'E', '5181']

SOLUTION: 15170

PROBLEM: ['7921', 'Y', 'G', '813', '4599', 'B', 's', 'M', '7171', '9033']

SOLUTION:
29537