interface MathConstants{
	double PI_VALUE = 3.14;
	int VALUE = 10;

	void fun();

	default void calculate(int a, int b){
		System.out.println(a + b);
		subtract(a, b);
	}
	
	static void sum(int a, int b){
		System.out.println(a + b);
	}
	
	private void subtract(int a, int b){
		System.out.println(a - b);
	}
}

class Random implements MathConstants{
	public void fun(){
		System.out.println(PI_VALUE);
	}
}
class Ideone
{
	public static void main (String[] args)
	{
		MathConstants f = new Random();
		f.fun();
		f.calculate(9,6);
		MathConstants.sum(2,6);
	}
}