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: ['9905', 'm', 'Q', 'S', 'T', '7821', '1773', '9515', '3963', '2931', '7023', '8677', '1739', 'O', '909', '9153', '8319', 'k', '2851']

SOLUTION: 74579

PROBLEM: ['J', '5149', 'H', 'L', 'm', 'h', '3863', 'n', 'z']

SOLUTION: 9012

PROBLEM: ['9077', '9447', '1793', '9385']

SOLUTION:
29702