jumptab (a)
{
  int b;
  switch (a)
    {
    case 0:
      b = 6;break;
    case 1:
      b = 5;break;
    case 2:
      b = 4;break;
    case 3:
      b = 3;break;
    case 4:
      b = 2;break;
    case 5:
      b = 1;break;
    }
  return b;
}