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: ['8591', 'J', 'l', 'l', '7023', 'N', 'n']

SOLUTION: 15614

PROBLEM: ['2913', 'b', 'j', '7591', 'O', 's', '5589', '4995', '7503', 'U', 'S', 'C', '6797']

SOLUTION: 35388

PROBLEM: ['3815', '8531', '465', 'y', 'C', 'F', 'B', 'q']

SOLUTION:
12811