fun sum (l) {
  case l of
    {}    -> return 0
  | h : t -> return (h + sum (t))
  esac 
}

fun print_list (l) {
  case l of
    {}    -> skip
  | h : t -> write (h); print_list (t)
  esac
}

fun array_to_list (a) local l, i {
  l := {};
  for i := a.length, i > 0, i := i-1 do
    l := a[i-1] : l
  od;
  return l
}

n := read ();
write (sum ({}));
write (sum ({1, 2, 3, 4, 5}));
write (sum (1:2:3:4:5:{}));
print_list (array_to_list ([1, 2, 3, 4, 5]))