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: ['6551', 'm', '3941', 'F', 'K', 'u', '7981', '9581', 'X', 'M', 'N', 'e', 'G', 'i']

SOLUTION: 28054

PROBLEM: ['c', 'r', 'R', 'a', '6915', 'C', '3651', 'j', 'L', '9761', '2923', 'Z', 'e', '833', 'W', '1867', 'G', 'H', 'T']

SOLUTION: 25950

PROBLEM: ['5559', '5217', 'D', '5853', 'U', '5455', '2097', '4651', '7643', '7733', 'y', 'T', '2203', 'P', 'W', '4645', '8981']

SOLUTION:
60037