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: ['x', 'd', '5121', 'I', '6737', '3789', '6167', 'C', '8947', 'k', '4715', '1885', 'H', 'B', '5685', 'S', '4615', 's', '7709']

SOLUTION: 55370

PROBLEM: ['W', '4453', '5895', 'Z', 'A', '7663', '2749', 'f', 'H', '6917', '1215', 'M', '1775', '5397', 'l', '8197', '5209', '8229', 'U']

SOLUTION: 57699

PROBLEM: ['6109', '2261', '9159', 'e', '4989', '7645', '4147', 'b']

SOLUTION:
34310