Given the task definition, example input & output, solve the new input case.
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
Output: 3
Here, 'sottrazione' represents the subtraction operation. So, the answer is 3 (10-7=3).

New input case for you: 5400 aggiunta 7436 aggiunta 7870
Output:
20706