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: ['4701', 'b', 'i', 'B', 'z', '7837', 'W']

SOLUTION: 12538

PROBLEM: ['4515', '3911', 'M', 'T', 'w', 'F']

SOLUTION: 8426

PROBLEM: ['C', '5193', 'D']

SOLUTION:
5193