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: ['D', 'R', 'Y', '4929', 'P', '7929']

SOLUTION: 12858

PROBLEM: ['4607', 'T', 'a', '6077', 'c', '4761']

SOLUTION: 15445

PROBLEM: ['8943', 'I', '8271', '2425', '9115', 'X', 'f', '1935', 'Y', 'h', 'e']

SOLUTION:
30689