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

public class StudAcc
{
	public static void main(String args[]) throws Exception
	{
		TreeSet oldAcc = new TreeSet();
		TreeSet currAcc = new TreeSet();
		TreeSet gradAcc = new TreeSet();
		TreeSet newAcc = new TreeSet();
		
		try
		{
			readAccounts("F:\\oldAcc.txt", oldAcc);
			readAccounts("F:\\currAcc.txt", currAcc);
		}
		
		catch(IOException ioe)
		{
			System.out.println("Cannot open file");
			System.exit(1);
		}
	
		gradAcc.addAll(oldAcc);
		gradAcc.addAll(currAcc);
		
		newAcc.addAll(gradAcc);
		newAcc.removeAll(oldAcc);
	
		System.out.println(oldAcc);
		System.out.println(currAcc);
		System.out.println(gradAcc);
		System.out.println(newAcc);
	
		writeFile("F:\\gradAcc.txt", gradAcc);
		writeFile("F:\\newAcc.txt", newAcc);
		
		System.out.println("Data save to the file...");
	}
	
	public static void readAccounts(String filename, TreeSet accs) throws Exception
	{
		Scanner sc = new Scanner(new FileReader(filename));
		String accName;	
		int counter = 0;
		while (sc.hasNext())
		{
			accName = sc.next();
			counter++;
			if ((counter>3) && (counter%2 == 0))
			{
				System.out.println(accName);
			  	accs.add(accName);
			}
		} 
	}
	
	public static void writeFile(String fileName, TreeSet s) throws Exception
	{
		FileWriter fw = new FileWriter(fileName);
	  	PrintWriter p = new PrintWriter(fw);
	   	
	  	//Iterator;
	  	Iterator iter;	  
	  	iter = s.iterator();
	  	String item="";
	  	while (iter.hasNext())
	  	{
	  		item = (String) iter.next();
	  		p.println(item);
	  	}
	  	p.close(); 
	}
}