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: ['r', '3537', 'T', '3611', 'k', '4983', 'h', '4317', '8727', 'E', '6471', '8465', 'f', '5429', 'T', '2169', '2171', 'P', '6941', 'D']

SOLUTION: 56821

PROBLEM: ['K', '5815', 'E', 'c', '7379', '4995', 'w', 'B', 'j', '6227', 'B', '733', '1491', '3191', '9413', '2751', 'O', 'J', '6239', '3521']

SOLUTION: 51755

PROBLEM: ['6441', '4983', 'w', 'l', 'y', '4061', '8707']

SOLUTION:
24192