import java.util.*;
import java.lang.*;
import java.io.*;


import java.util.Scanner; 
public class Area { 
public static void main(String[] args) { 
int r; 
double pi = 3.14, area; 
Scanner s = new Scanner(System.in);
System.out.print("Enter radius of circle:"); 
r = s.nextInt(); 
area = pi * r * r; System.out.println("Area of circle:"+area);
} 
}