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: ['4425', 'x', '1959', 'C', 'c', 'D', 'M', '8317', 'q', 'x', '4277', 'N', 'z', 'I', '1921', 'o', 't']

SOLUTION: 20899

PROBLEM: ['7709', 'y', 'k', '8137', '5337', '6419', '5449', 'g', 'H', 'e', '311', '9315', 'Z', 'Z']

SOLUTION:
42677