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: ['x', '9895', 'r', 'H', 'C']

SOLUTION: 9895

PROBLEM: ['t', '7469', 'Y', 'N', '8137']

SOLUTION: 15606

PROBLEM: ['215', '3361', 'Z', 'o']

SOLUTION:
3576