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: ['6867', 'x', '8481', '5091', '979', 'a', 'S', 'i', 'd', '1591']

SOLUTION: 23009

PROBLEM: ['y', '6511', 'c', 'c', '3947', '6371', '1599', 'X']

SOLUTION:
18428