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: ['2013', 'S', 's', '9353', 'b', 'u', '6687', '5429', '3545', '7269']

SOLUTION: 34296

PROBLEM: ['6367', '9923', '9141']

SOLUTION: 25431

PROBLEM: ['2957', '9009', 'c', '2763', '8687']

SOLUTION:
23416