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: ['z', 'j', 'M', 'E', '1689', '8413', '2603', 'b', '5101', 'w', 'r']

SOLUTION: 17806

PROBLEM: ['57', '9977', '2657', 'p', '9573', '7745', '4755', 'U']

SOLUTION: 34764

PROBLEM: ['6457', 'c', '4383', '6623', '4467', '9525', 'P', 'O']

SOLUTION:
31455