In this task you will be given an arithmetic operation in Italian and you have to find its answer. The operations 'addition' and 'subtraction' have been replaced with their italian translations i.e you need to perform addition when you see 'aggiunta' and subtraction in case of 'sottrazione'.
Example: 10 sottrazione 7
Example solution: 3
Example explanation: Here, 'sottrazione' represents the subtraction operation. So, the answer is 3 (10-7=3).

Problem: 4574 aggiunta 2928 aggiunta 9854 aggiunta 3542 sottrazione 5199 aggiunta 2487 sottrazione 6935 aggiunta 4615

Solution: 15866