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: 6138 aggiunta 3496 sottrazione 8899 sottrazione 3209 aggiunta 5714 sottrazione 5744 sottrazione 5115 aggiunta 8145

Solution: 526