// -*- rust -*-

fn main() {
  check(even(42));
  check(odd(45));
}

fn even(int n) -> bool {
  if (n == 0) {
    ret true;
  }
  else {
    be odd(n - 1);
  }
}

fn odd(int n) -> bool {
  if (n == 0) {
    ret false;
  }
  else {
    be even(n - 1);
  }
}