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: ['k', '6555', 'L', '7549', 'W', 'y', 'y', '8817', 'J', 't', 'X', 'M', 'N', 'G', '7441', '283']

SOLUTION: 30645

PROBLEM: ['2787', '6085', '6989']

SOLUTION: 15861

PROBLEM: ['7285', 'u', 'w', '9423', 'R', '6263', 'v', 'W', '7257', '7605', 'x']

SOLUTION:
37833