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: ['W', 'c', 'P', '425', '4133', 's', '1831', '883', '2531', '681', 'U', 'B', 'H', '237', '4245']

SOLUTION: 14966

PROBLEM: ['z', 'T', 'Y', 's', 'j', '585', '7833', '2601', '8057', 'S', '7037', '5799', '4477', '5377', '6301', 'P', 'm', '9431', 'f']

SOLUTION: 57498

PROBLEM: ['9069', '8333', 'H', '2049', '8051', 'L', '2749', '8819', '2883', '9317', 'M', '6515']

SOLUTION:
57785