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 input: 10 sottrazione 7
Example output: 3
Example explanation: Here, 'sottrazione' represents the subtraction operation. So, the answer is 3 (10-7=3).
Q: 4955 sottrazione 7166 aggiunta 9808 sottrazione 5122 sottrazione 4635 aggiunta 6157
A:
3997