Ask for a movie about mental patients

Fatal curve 4 has aroused great concern. In the fourth part, a group of friends decided to go sledding in the winter vacation. They made a "fatal bend" and got lost in the snowstorm, and then they found shelter in an abandoned nursing home. They were completely isolated by the snowstorm, and they were lucky to escape the natural disaster. But the sanatorium they found has a terrible past, and the patients living in this sanatorium are still alive. These patients are very disgusted with their invasion. A deadly "cat and mouse" game has begun. These children who are still in college must fight, or they will not survive all night. At this critical moment, they can only rely on their own wisdom to survive.