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: ['f', 'N', '8597', 't', 'K', '9755', 'j', '9747', '7259', '5493', 'n', '7269', '8493', '2279', '5369', 'f']

SOLUTION: 64261

PROBLEM: ['U', '5885', 'u', 'Y', 's', 'w', 'j', '9629', '9505', 'U']

SOLUTION: 25019

PROBLEM: ['419', '8781', '3671', '9129', '3121', '7815', '3341', '3923', '3225', '1187', '5065', 'i', '6191', 'q', 'z', '9911', '8307', '4627', '5323', 'u']

SOLUTION:
84036