program queue;
var que:array[0..10]of integer;
    n,i,j,a,b,long:integer;
    f1,f2:text;
begin
 assign(f1,'queue.in');
 reset(f1);

 assign(f2,'queue.out');
 rewrite(f2);

 readln(f1,n);

 for j:=1 to n do
 begin
  read(f1,a);

  case a of
   1:begin
      for i:=1 to long do
       que[i]:=0;
      long:=0;
     end;
   2:if long<10 then
     begin
      read(f1,que[long+1]);
      long:=long+1;
     end else writeln(f2,'queue out');
   3:if long>0 then
     begin
      que[1]:=0;
      for i:=1 to long-1 do
       que[i]:=que[i+1];
      long:=long-1;
     end else writeln(f2,'queue empty');
   4:begin
      writeln(f2,long);
      for i:=1 to long do
       write(f2,que[i],' ');
     end;
  end;
 end;

 close(f1);
 close(f2);
end.