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: ['x', '1887', 'E', '3995', '5677', '2749', '9951']

SOLUTION: 24259

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

SOLUTION: 74579

PROBLEM: ['3719', 'Z', 'M', '5741', '9943', '6825', 'S', '3917', '63', '205', '9155', 'K', '8579', '2335', 'O', '5401', '919', 'i', '603']

SOLUTION:
57405