// Copyright 2015 the Dart project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file.

void main() {
  var i = 20;
  print('fibonacci($i) = ${fibonacci(i)}');
}

/// Computes the nth Fibonacci number.
int fibonacci(int n) {
  return n < 2 ? n : (fibonacci(n - 1) + fibonacci(n - 2));
}