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', '4181', 'g', 'j', '1823', 'q', 'i', '709']

SOLUTION: 6713

PROBLEM: ['7411', 'Y', 'x', 'l', '4119', '7241']

SOLUTION: 18771

PROBLEM: ['J', '4971', '7003']

SOLUTION:
11974