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: ['4177', 'd', 'b', 'm', 'f', 'R', '797', '7905', '4355', '7515', '9801', 'F', 'R', '9125', '8445', 'k', 'K', 'K']

SOLUTION: 52120

PROBLEM: ['4997', '5005', '6773', 'q', 'K', '8391', '7303', 'K', 'N', '5417', '8573', 'z', '8653', '8343', 'm', 'L', '1587', 'p', '5323']

SOLUTION: 70365

PROBLEM: ['R', '1853', '6687', 'l', 'i', 'c', '2447', 'e', 'p', 'c', '8989', 't', 'j', '5965', '3329', '4013', 'M']

SOLUTION:
33283