import java.util.HashSet;

public class Task250425 {
    public static void main(String[] args) {
        HashSet<String> set = new HashSet<>();
        
        String s1 = new String("hello");
        String s2 = new String("hello");
        String s3 = "hello";
        String s4 = s1.intern();
        
        set.add(s1);
        set.add(s2);
        set.add(s3);
        set.add(s4);
        set.add(null);
        set.add(null);
        
        System.out.println(set.size());
    }
}

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class ToListExample {
    public static void main(String[] args) {
        Stream<String> stream = Stream.of("apple", "banana", "orange");
        List<String> list = stream.collect(Collectors.toList());
        System.out.println(list); // [apple, banana, orange]
    }
}

import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class ToSetExample {
    public static void main(String[] args) {
        Stream<String> stream = Stream.of("apple", "banana", "apple");
        Set<String> set = stream.collect(Collectors.toSet());
        System.out.println(set); // [apple, banana]
    }
}