Java determine the circumference of a circle

import java.util.*;

class Circumference{



final static double pi=3.14;

public static double circum(double r){

    return 2*pi*r;

}

public static void main(String[]args){

Scanner input=new Scanner(System.in);

System.out.println("Enter radius: ");

double r=input.nextDouble();

double circumferenceOfCircle=Circumference.circum(r);

System.out.println("Circumference of  Circle: "+circumferenceOfCircle);

}

}