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: ['K', '479', 'u', '3489', 'o', '9589', '7153', '7649', '123', 'a', 'A', '3951', '847', 'N', 'R', '947', '9243', 'G', 'a']

SOLUTION: 43470

PROBLEM: ['4811', 'Q', '2289', 'N', 'I', '7681', 'z', '8179', '3359', '5299', 'R', 'z', '8697', '5781', '4803', '2715', '6511', '1371']

SOLUTION: 61496

PROBLEM: ['t', 'v', 'B', 'Y']

SOLUTION:
0