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: ['K', 'p', '97', 'R', '2999', 'u', '7307', '6033', '6431', 'm', 'T']

SOLUTION: 22867

PROBLEM: ['3809', '9401', '63', '5705', 'u', '6275', 'k', 'l', '1171', '9365', 'L', 'O', '7431', '8567', 'h', '6135']

SOLUTION: 57922

PROBLEM: ['1969', 'R', '5989', 'd', '8507', '5925', 'T', 'D', 'd', 'H', 'F', 'q', '8365', 'D', 'N', 'k', '5061', '4859']

SOLUTION:
40675