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: ['N', 'V', 't', 'X', 't', 'M']

SOLUTION: 0

PROBLEM: ['3839', 'D', '4741', 'L']

SOLUTION: 8580

PROBLEM: ['6469', '3027', 'Z', '3353', 'a', 'S', '3879', '8471', 'H', 'I', 'y', '2661', '9007', 'D']

SOLUTION:
36867