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: ['251', '2155', '5029', 'k', 'j', 'I']

SOLUTION: 7435

PROBLEM: ['5499', '39', 'Q', 'b', 'W', '7155', '2515']

SOLUTION: 15208

PROBLEM: ['6563', 'R', 'M', 'B', 'b', 'E', '9911', '7327', 'J', '7389', 'w', 'b', 'c', '1527', 'K', 'r', '5441', '6823', '8455']

SOLUTION:
53436