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: ['e', 'K', 'A', 'V', '1169', 'n', '8729', 'V']

SOLUTION: 9898

PROBLEM: ['251', '2155', '5029', 'k', 'j', 'I']

SOLUTION: 7435

PROBLEM: ['7639', 'c', 'S', '9489']

SOLUTION:
17128