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: ['a', 'f', '2185', 'N', '6381', '6429', '7499', 'd', '757', 'k', 'k', 'b', 'N', '2697', 'A', '8037']

SOLUTION: 33985

PROBLEM: ['s', 'M', 'U', '5383']

SOLUTION: 5383

PROBLEM: ['8139', 'P', '5251', 'Q', 'q', 'f', 'k', '3803', '1787', 'y', '7751']

SOLUTION:
26731