Hello. This book was originally featured by Kajiatan Posky (UK). When the book changed languages, there were some deviations, resulting in some passwords missing.

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The correct password is 429.

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After breaking the article information:

Well done, you must be a genius like me, pay attention to my other demon challenges.

In the math book of killing people

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Please forgive me for the nonstandard translation.

Well done, you must be a genius, just like me. But be careful of my other demons' challenges in other math books!

The above is professor devil's tone, which is what it means in translation.

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Starry night の answer. Please adopt it.