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: ['E', 'v', 'l', 'c', 'g', '3929', 'q', 'j']

SOLUTION: 3929

PROBLEM: ['r', '6537', '3001', '7879']

SOLUTION: 17417

PROBLEM: ['4619', 'Q', '1131', 'Y', 'v', 'C', 'F', 's', 'n']

SOLUTION:
5750