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: ['8669', '9115', '2573', '9261']

SOLUTION: 29618

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

SOLUTION: 7971

PROBLEM: ['A', 'o', 'F', '5901', 'b', '3135']

SOLUTION:
9036