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: ['6731', 'f', '4561', '5601', 'i']

SOLUTION: 16893

PROBLEM: ['w', '8035', 'J', '2671', '7509', '1573', '6915', '8569', '345', 'T', 'P', 's', '1341', '7823', '8671', 'm', 'Q', 's', 'N']

SOLUTION: 53452

PROBLEM: ['9869', 'u', '4427', '1181', 'p', '7497', 'K', 'J', 'y', '4589', '4863', 'K', 'J', '2945', 'S']

SOLUTION:
35371