import java.util.*;
import java.io.*;

public class FirstSet
{
	public static void main(String[] args) throws Exception
	{
		Scanner input = new Scanner(System.in);
		PrintStream output = System.out;
		
		Set<Integer> set = new TreeSet<Integer>();
		output.println("Enter integers [sentinel=-1]");
		for (int num = input.nextInt(); num != -1; num = input.nextInt())
		{
			set.add(num);
		}		
		output.println(set);
	}
}