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This is an iron rope made of magic. You can't break free using brute force. But it doesn't matter, you are a wizard too and you try to defeat magic with magic. But you failed. You have to re-examine the iron chain, and find that it is actually composed of letters that emit light, and is connected with many symbolic links that you recognize individually, but cannot understand when combined, and finally form inequalities. Intuition tells you that the key to breaking the shackles of magic is to solve these inequalities. But the question is...[If... F'(x)≥1/4, f(2)≥0, x≥3... Max{f(x)}=?] "???" "Whose magic is used like this?"

"Why is this fireball technique green?" "Well... Because I added poisonous gas to it." "What about the ice pick technique? Why did you fall to the ground after being hit? Is it also poisonous?" "No, it's just a powerful anesthetic." "What about the magical girl apprentice you summoned? Why does she know Taekwondo?" "How normal, girls have to learn some skills to defend themselves, isn't it..." "??? So you don't follow the routine at all?"

Boom! "???" "Our mission is just to eliminate the suspects hiding in the building. Who jumped on the horse and blew up the building?!" "Wait a minute, isn't this a horror survival game about trying to survive seven days? Why is he outside killing monsters alone?" "I repeat. Again, the task of protecting Miss Sha Ya is very difficult. I hope everyone will be alert... Wait a minute, I'll answer the phone... What? Miss Sha Ya ran away with a man? "" Damn, who is this person? "