/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.util.stream.Collectors;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		List<Integer> list = Arrays.asList(1, 2, 3, 4, 4, 5, 6, 7, 7, 8, 9, 10, 11, 11, 11, 11, 11, 12, 12, 13, 13, 13, 13);
        List<Integer> removed = list.stream().distinct().collect(Collectors.toList());
        System.out.println(removed);
	}
}