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: ['J', '5149', 'H', 'L', 'm', 'h', '3863', 'n', 'z']

SOLUTION: 9012

PROBLEM: ['t', 'x', '5629', 'k', '2003', 'v', '541', 'l', 'v', '7983', '677', '6173', 'z', 'J', 's', 'u', '2187', 'Y']

SOLUTION: 25193

PROBLEM: ['6367', '6673']

SOLUTION:
13040