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', '7807', '9395', 'T', 'c', '5139', '2827', 't', 'T', 'm', '3717', 'U', '3225', '7419', '2481', 'p', 'C', '5277']

SOLUTION: 47287

PROBLEM: ['m', '3481']

SOLUTION: 3481

PROBLEM: ['3481', 'Q']

SOLUTION:
3481