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: ['6019', '1467', '3415', '7785']

SOLUTION: 18686

PROBLEM: ['x', '5259', 'T', 'L', 'C', 'H', '2493', 'u', '3851', '2439', 'U']

SOLUTION: 14042

PROBLEM: ['6653', 'h', 's', '5717', '4517', '7669', 'k', '8889', 'A', '8485', '8985', '5187', 'v', '733', '7343', 'y', 'P', 'O', '6717']

SOLUTION:
70895