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

SOLUTION: 57922

PROBLEM: ['l', 'B', 'Y', '7543', '5091', '1917']

SOLUTION: 14551

PROBLEM: ['M', 'e', '789', '5691', '6931', '9909', '1745', '5347', 'A', 'P', '9541', 'm', '1811', '2585']

SOLUTION:
44349