procedure TForm1.Button1Click(Sender: TObject);
var pepe:tstringlist;
i,p:integer;
begin
pepe:=tstringlist.Create;
pepe.add('555');
pepe.add('333');
pepe.add('555');
pepe.Sort;
i:=0;
while i <= pepe.Count-1 do
begin
if (pepe.Find(pepe[i],p)) and (i<>p) then
pepe.delete(p);
inc(i);
end;
memo1.lines:= pepe;
end;