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.
--------
Question: ['a', 'j', 'v', '619', 't', 'a', '5777', 'x', 'R', 'P', '8897', 'j']

Answer: 15293


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

Answer: 18686


Question: ['4529', '7465', 'S', 'Z', 'v', 'w', '5791', '3363', '2643']

Answer:
23791