n := read ();

case 3 of
  a -> write (a)
| _ -> write (0)
esac;

case 3 of
  a -> write (a)
esac;

case 3 of
  a@_ -> write (a)
esac;

case `a (1, 2, 3) of
  `a             -> write (1)
| a@`a (_, _, _) -> case a of
                     `a (x, y, z) -> write (x); write (y); write (z)
		    esac
esac;

case `a (1, 2, 3, 4, 5) of
  `a                 -> write (0)
| `a (_)             -> write (1)
| `a (_, _)          -> write (2)
| `a (_, _, _)       -> write (3)
| `a (_, _, _, _)    -> write (4)
| `a (_, _, _, _, _) -> write (5)
esac;

write (`a (1, 2, 3, 4, 5).length);

write (`a (1, 2, 3, 4, 5)[0]);
write (`a (1, 2, 3, 4, 5)[1]);
write (`a (1, 2, 3, 4, 5)[2]);
write (`a (1, 2, 3, 4, 5)[3]);
write (`a (1, 2, 3, 4, 5)[4])