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: ['3433', '6955', 'Q', 'E', '3557', 'S', '2931', '9879', 'S', 'f', 'Q']

SOLUTION: 26755

PROBLEM: ['2871', '1337', '3771', '4671', 'l', '3785', 'V', 'z', 'R', 'u', '6097', 'R', '4297', 'd', '6339', 'Y', 'V', '5873', '7399']

SOLUTION: 46440

PROBLEM: ['6325', '2487', 'd', 'c', '3385', 'x', 'q', 'T', 'd', '5127', '4503', 'T']

SOLUTION:
21827