import java.io.*;

class Editor1
{
// A simple text editor program

 public static void main(String[] args)
 throws IOException
 {
  BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
  InsertList2 lines = new InsertList2();
  char ch;
  String command,line;
  do {
      System.out.print(": ");
      command = in.readLine();
      ch = command.charAt(0);
      switch(ch)
        {
         case 'i' :
            do {
                line = in.readLine();
                if(line.length()==1&&line.charAt(0)=='.')
                   break;
                lines.insert(line);
               }
            while(true);
            break;
         case 'd' :
            if(lines.isEmpty())
	       System.out.println("?");
	    else
	       {
		lines.delete();
		if(!lines.isEmpty())
                   System.out.println(lines.current());
	       }
            break;
         case '+' :
            if(lines.isEmpty()||lines.atEnd())
               System.out.println("?");
            else
               {
                lines.forward();
                System.out.println(lines.current());
               }
            break;
         case '-' :
            if(lines.isEmpty()||lines.atStart())
               System.out.println("?");
            else
               {
                lines.backward();
                System.out.println(lines.current());
               }
            break;
         case 'p':
            if(lines.isEmpty())
               System.out.println("?");
            else
               System.out.println(lines.current());
            break;         
         case 'l':
            System.out.print(lines);
            break;
         case 'q': break;
         default: 
             System.out.println("?");
        }    
     }
  while(ch!='q'); 
 }
}