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: ['m', '6153', 'A', '6173', 'x', '7527', '8501', 'g', 'r', 'K', 'I', '3103', '8347']

SOLUTION: 39804

PROBLEM: ['2787', 'z', '9351', '3339']

SOLUTION: 15477

PROBLEM: ['6781', '5121', 'z', 'z', '2675', 'T', 'O', '625', '8969', 'd', '471', 'T', 'i', '2785', '2875', 'S', '775']

SOLUTION:
31077