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: ['P', '6161', 'k', '5925', 'h', 'G', 'n']

SOLUTION: 12086

PROBLEM: ['N', '1337', 'C', 'T', '863', 'j', '2369', 'P', 'A', 'x', '5725', '2333', 'Q', '9149', 'Q', '8529', 'N']

SOLUTION: 30305

PROBLEM: ['5391', 'a', '703', '8259', '5097', '8105']

SOLUTION:
27555