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

SOLUTION: 46440

PROBLEM: ['9069', '8333', 'H', '2049', '8051', 'L', '2749', '8819', '2883', '9317', 'M', '6515']

SOLUTION: 57785

PROBLEM: ['R', '185', 'a', '8815', '6229', '3221', '6025', 'U', 'i', 'E', 'S', 'a']

SOLUTION:
24475