Where can I get pistachio nuts for the parrot?

Hint 1 of 9:

Have you been to your Second Class room?

Hint 2 of 9:

There's a bowl of pistachio nuts next to the bed.

Hint 3 of 9:

You can't pick up the nuts, so you're going to have to take the parrot to
them.

Hint 4 of 9:

Grab the parrot out of his cage and put him in your inventory.