Jester was sitting at a table in the library. Sammy thought that he was unusually quiet and went to check on him. When he looked over Jester's shoulder, he saw a piece of paper with this written on it.

What digit, when 3 of itself are added together, equals 12? The answer is not 4.

"Where did you get this from?" Sammy asked Jester.

"His Majesty gave this to me." Jester groaned back. "He says I can't enter the throne room until I figure this problem out."

"There are only 9 digits. What is stopping you from guessing?" Sammy asked as he sat down next to Jester.

"The king said I have one chance to answer. If I get this wrong, I have to go on an expedition with Knight into the forest. If I do get the correct answer, I have to prove it is correct. If I can't prove it, expedition it is..." Jester replied.

As Jester slumped onto the table, Sammy thought to himself, 'It's been a while since I've been hiking. Maybe I should join the expedition.'