program nome (input,output);

type
   stringa = packed array[1..20] of char;
   TP	   = record
		time	: integer;
		bef,aft	: stringa;
	     end;	

var n,m,mintempo       : integer;
   product	       : integer;
   patch	       : array[1..100] of TP;
   programma,soluzione : stringa;
   ricordi	       : array[1..200] of stringa;
   trovata	       : boolean;

procedure Leggi;
var i,j	: integer;
   ch	: char;
begin

   for i:=1 to 20 do begin
      programma[i]:='+';
      soluzione[i]:='-';
   end;

   for i:=1 to m do with patch[i] do
   begin
      read(time);
      read(bef[1]);
      while bef[1]=' ' do read(bef[1]);
      for j:=2 to n do read(bef[j]);
      read(aft[1]);
      while aft[1]=' ' do read(aft[1]);
      for j:=2 to n do read(aft[j]);
      readln;
   end;
   for i:=n+1 to 20 do programma[i]:='-';
end;

function applicabile(q	:integer ):boolean;
var i : integer;
begin
   applicabile:=true;
   for i:=1 to n do
      if patch[q].bef[i]<>'0' then
	 if patch[q].bef[i]<>programma[i]
	    then applicabile:=false;
end;

procedure esegui(q ,lvl:integer );
   var i : integer;
begin
   ricordi[lvl]:=programma;
   for i:=1 to n do
      if (patch[q].aft[i]<>'0')
	 then programma[i]:=patch[q].aft[i];
end; { esegui }


procedure deesegui(lvl :integer );
begin
   programma:=ricordi[lvl];
end; { deesegui }

function giafatto(lvl :integer ):boolean;
var i:integer;
begin
   giafatto:=false;
   for i:=1 to lvl-1 do
      if ricordi[i]=programma then
	 giafatto:=true;      
end;

procedure applica(i ,lvl, tempo:integer );
var tmp,j : integer;
   
begin
{applicazione}
   esegui(i,lvl);
   if (not giafatto(lvl)) and (lvl<20 ) then
   begin
      tmp:=tempo+patch[i].time;
      for j:=1 to m do
      begin
	 if programma=soluzione then
	 begin
	    trovata:=true;
	    if tmp<mintempo
	       then mintempo:=tmp;
	 end else
	 begin
	    if applicabile(j) then
	       if (tmp<mintempo) and (j<>i) then
		  applica(j,lvl+1,tmp);
	 end;
      end;
   end;
   deesegui(lvl);
end;

procedure elabora;
var i :integer;
begin
   mintempo:=maxint;
   for i:=1 to m do
   begin
      if applicabile(i) then
	 applica(i,1,0)
      else
	 {nodo terminale}
   end;
end;

procedure Scrivi;
var i : integer;
begin
   writeln('Product ',product:1);
   if trovata then
      writeln('Fastest sequence takes ',mintempo:1,' seconds','.')
   else
      writeln('Bugs cannot be fixed.');
   writeln;
end;

begin
   reset (input,'bugs.in');

   product:=0;
   read(n,m);
   while ((n<>0) and (m<>0)) do
   begin
      trovata:=false;
      product:=product+1;
      readln;
      leggi;
      elabora;
      scrivi;
      read(n,m);
   end;
   
   close(input);
end.