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', '5571', '6455', '4287', 'I', 'U', 'M', '8303', '8893']

SOLUTION: 33509

PROBLEM: ['3451', '2325', '2511', 'i', '6159', '2291', 'e', 'l', 'P', '1177', 'o', 'T']

SOLUTION: 17914

PROBLEM: ['6679', '4525']

SOLUTION:
11204