trait Show {
    fn show(self: Self) -> void;
}

struct Point { x: i64, y: i64 }

extend Show Point {
    fn show(self: Point) -> void {
        print_i64(self.x);
        print_i64(self.y);
    }
}

fn main() -> i64 {
    let p = Point { x: 10, y: 20 };
    p.show();
    return 0;
}