// Copyright (c) 2019-present, Facebook, Inc.
// All rights reserved.
//
// This source code is licensed under the license found in the
// LICENSE file in the root directory of this source tree.
//

import java.util. *;
import java.util.stream.*;
import java.lang.*;
import javafx.util.Pair;
public class AREA_OF_THE_CIRCLE_THAT_HAS_A_SQUARE_AND_A_CIRCLE_INSCRIBED_IN_IT{
static float f_gold ( int a ) {
  float area = ( float ) ( Math . PI * a * a ) / 4 ;
  return area ;
}
}