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

class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Process tr = Runtime.getRuntime().exec(new String[]{"cat"});
                Writer wr = new OutputStreamWriter( tr.getOutputStream() );
                BufferedReader rd = new BufferedReader( new InputStreamReader( tr.getInputStream() ) );
		wr.write( "hello, world\n" );
		wr.flush();
		String s = rd.readLine();
		System.out.println( s );
	}
}