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', 'a']

SOLUTION: 0

PROBLEM: ['2417', '6671']

SOLUTION: 9088

PROBLEM: ['9945', '4847', '4871', '8299', '9569']

SOLUTION:
37531