Circle: Diameter,Circumference,Area

Problem: Write a Java Program that calculates and prints the diameter, circumference, or the area of a circle given the radius. The application should input a character corresponding the one of the three actions:
           
             D-  Diameter
             C-  Circumference
             A-  Area


CODE:

package circle;
import java.util.Scanner;

public class Circle {
    static Scanner gene=new Scanner(System.in);

    public static void main(String[] args) {
        char choice;
        String input;
        int rad;
        double ans;
   
        System.out.println("**PLEASE CHOOSE**");
        System.out.println("[D]iameter");
        System.out.println("[C]ircumference");
        System.out.println("[A]rea");
        System.out.println("Enter your Choice:");
        input=gene.next();
        choice=input.charAt(0);
        System.out.println("Enter the radius of the circle:");
        rad=gene.nextInt();
   
        switch(choice){
            case 'D': case 'd': System.out.println("Diameter");
             ans=2*rad;
            System.out.println("Answer:"+ans);
             break;

       
            case 'C': case 'c': System.out.println("Circumference");
            ans=2*3.14159265*rad;
            System.out.println("Answer:"+ans);
            break;

       
             case 'A': case 'a': System.out.println("Area");
             ans=3.14159265*rad*rad;
            System.out.println("Answer:"+ans);
            break;

default: System.out.println("INVALID INPUT");break;
 
             }

      }
}