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: ['2765', '6767', '7645']

SOLUTION: 17177

PROBLEM: ['o', 'a', 'K', '6031']

SOLUTION: 6031

PROBLEM: ['47', '1265', '8345', '1647', '9067', '1221', 's', 'B']

SOLUTION:
21592