My Life Goes By My Style

import java.io.*;
public class ch3{
public static void main(String[] args)throws IOException
{
BufferedReader input = new BufferedReader
(new InputStreamReader(System.in));

final float PI=3.14f;
int r;
float area;
float girth;
System.out.print("請輸入需要半徑 :");
r=Integer.parseInt(input.readLine());
area=r*r*PI;
girth=2*PI*r;
System.out.println("您輸入的半徑為 :"+r+"\n圓周率為: "+PI+"\n圓面積為: " +area+"\n圓周長為 :"+girth);

}
}