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'.
Q: 9177 aggiunta 3957 aggiunta 6907 sottrazione 9729 aggiunta 4954 sottrazione 6374
A: 
8892