/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

interface Itf {
  public default int fib(int a) {
    if (a <= 1) return a;
    return fib(a - 1) + fib(a - 2);
  }
}

public class Main implements Itf {

  public static void main(String[] args) {
    int result = new Main().fib(2);
    if (result != 1) {
      throw new Error("Expected 1, got " + result);
    }
  }

  public int fib(int a) {
    return Itf.super.fib(a);
  }
}