"But what set of numbers is this? I think if we guess wrong, we can't be safe, right? Otherwise, people don't have to make such trouble? Zhang Mei kept those numbers firmly in her heart and asked her own questions.

"Hehe, that's right, this kind of design, in fact, it's the same as when we play computer games, if you can't beat the level, you're often going to be unlucky." Cheng Nan Xian was full of confidence, and he could still laugh.

"Do you have a way?" Seeing this, Zhang Mei's eyes lit up and said. "It's actually quite simple! If you think about it, the masked man just now was able to open the password, then naturally he knew this set of permutation passwords, and the stone password here is so big, I don't think he could have pressed it with his hands, and if he stepped on it with his feet..."Speaking of this, Chengnan suddenly stopped, and then raised his foot and stretched out in front of Zhang Mei. Zhang Mei was stunned for a moment and looked at his feet strangely, only to see that the feet of Chengnan were black and full of slime. Zhang Mei immediately understood, you must know that the only intersection here is through the hole above just now, and the hole above the hole is full of the black liquid at the foot of Chengnan just now, and several of her feet are actually stained with this liquid, and the mask man's feet must also be stained with this black liquid, so if he steps on the numbers with his feet, he only needs to look to see if there is this black liquid on the numbers other than 7-4-4-5, and he can tell which set of numbers he used just now. ”

"I'll take a look." As soon as she heard that there was hope to open the door, Zhang Mei became excited, and ran to the stone to examine it carefully.

"Seongnam come and see, look here.. There are traces of black slime here, so it should be the second password? Zhang Mei pointed to the stones in front of her feet and turned around excitedly.

Cheng Nan leaned down and confirmed: "That's right, it should be the second set of passwords." ”

"Let's try it now?" Zhang Mei asked.

"Okay." Seongnam looked at it, slowly stood up and nodded.

"Are you coming or am I coming?" Seongnam asked.

"I'll come." Saying that, Zhang Mei stepped on the first number.

"Click!" I heard a click, and the number with the Arabic numeral "7" written on it suddenly fell. “7..4..3…。” Zhang Mei ran from one side to the other like a monkey while chanting, and soon stepped on almost all the numbers.