import java.util.ArrayList;
import java.util.List;
public class Main {
public static void main(String[] argv) {
List<String> mascots = new ArrayList<>();
mascots.add("duke");
mascots.add("juggy");
String actual = mascots.stream().
reduce((t, u) -> t + "," + u).
get();
System.out.println(actual);
}
}