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: 1515 aggiunta 4661 aggiunta 6401 sottrazione 5458 sottrazione 4056 aggiunta 5633 aggiunta 3647 aggiunta 2726 aggiunta 5641

Solution: 20710