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: ['7231', '2813', '51', '1745', 'c', 'a', '4929', '3185', '5707', '2095', 'f', 'S']

SOLUTION: 27756

PROBLEM: ['8529', '2657', '1599', 'b', '8187', '7005', '7481']

SOLUTION: 35458

PROBLEM: ['o', 'U', '1181', 'T', '1193', '6329', '1987', '2553']

SOLUTION:
13243