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: ['w', 'I', 't', '813', 'K', '5785']

SOLUTION: 6598

PROBLEM: ['Y', '8169', '9067']

SOLUTION: 17236

PROBLEM: ['6901', 'O', 's', 'E', '5499', '5859', '21', '1997', '7213', 'H', 'f', 'S', 'F', '2799', 'A', '555', 'Z', 's', '3423']

SOLUTION:
34267