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

SOLUTION: 70365

PROBLEM: ['6787', 'W', 'I', '4929', 'j', 'I', '3487', 'F', '3927', 'Q', 's', 'X', '9939', 'n']

SOLUTION: 29069

PROBLEM: ['9323', '9961', 'c', '2103', '4523', '9815', '6541', 'F', 'U', 'N', '5733', 'J', '3853']

SOLUTION:
51852