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: ['b', '5689', '119', 'p', 'P', 'J', 'w', 'm', '7397', 'Y', '447', 'O', 'p', '319', 'H', 'U']

SOLUTION: 13971

PROBLEM: ['291', 'R', 'N', '983', '2879', 'C', '3797', '4837', '793', '5489', 'k', '535', 'L', '3605', 's', '3701', 'U', '4399', '2489', '4739']

SOLUTION: 38537

PROBLEM: ['L', '1205', 'x']

SOLUTION:
1205