The railway stipulates that passengers in hard-seat cars cannot cross the sleeper cars, which is also for the rights and safety of passengers in sleeper cars. It's like staying in the standard room of a hotel, and then you tell the waiter that you want to use the toilet in the presidential suite. Waiter, can you use it? If everyone with hard seats goes to the sleeper, the system will be chaotic and unfair to the sleeper passengers. Sleeper passengers pay twice the price, and then hard seat passengers can enter and leave the sleeper at will. Who will buy a sleeper after that?