#include <stdio.h>
#include "String.h"
#include "DList.h"

main ()
{
#ifdef CPLUS_BUG19
	IvlDList l;
#else
	IvlDListOf <char> l;
#endif
	char c;
	char s[80];
	while ((c = getchar ()) != EOF) {
		switch (c) {
		case 'a':
			scanf (" %s", s);
			l.Append (NewString (s));
			break;
		case 'p':
			scanf (" %s", s);
			l.Prepend (NewString (s));
			break;
		case '+':
			l.RemoveFirst ();
			break;
		case '-':
			l.RemoveLast ();
			break;
		case '\n':
			continue;
		case 'r':
			{
			IvlDListIterOf <char> li (l);
			li.GotoEnd ();
			while (--li) {
				char* pt = *li;
				printf ("%s ", pt);
			}
			printf ("\n");
			continue;
			}
		case 'i':
			{
			int i;
			scanf (" %d %s", &i, s);
			IvlDListIterOf <char> lj (l);
			while ((i-- > 0) && ++lj)
				;
			l.InsertBefore (lj, NewString (s));
			break;
			}
		case 'j':
			{
			int i;
			scanf (" %d %s", &i, s);
			IvlDListIterOf <char> lj (l);
			while ((i-- > 0) && ++lj)
				;
			l.InsertAfter (lj, NewString (s));
			break;
			}
		}
#ifdef CPLUS_BUG19
		IvlDListIter li (l);
		while (++li)
			printf ("%s ", (char*) *li);
#else
		IvlDListIterOf <char> li (l);
		while (++li) {
			char* pt = *li;
			printf ("%s ", pt);
		}
#endif
		printf ("\n");
	}
}