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: ['D', 'm', 'P', '2433', '6731']

SOLUTION: 9164

PROBLEM: ['2923', '3573', '6179', '7673', '6551', 'B', '315', '5169', 'm', '9405', 'm', 'Z']

SOLUTION: 41788

PROBLEM: ['4069', '7751', 'N', '8713', 'm', '7811', '1085']

SOLUTION:
29429