import java.util.TreeSet;

public class Task271025 {
    public static void main(String[] args) {
        TreeSet<Integer> set = new TreeSet<>();
        set.add(5);
        set.add(3);
        set.add(8);
        set.add(1);
        
        System.out.print(set.lower(4) + " ");
        System.out.print(set.higher(4) + " ");
        System.out.print(set.floor(3) + " ");
        System.out.print(set.ceiling(6));
    }
}