//by manssonlife

import java.util.Scanner;

public class No7 {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int radie1 = in.nextInt();

int radie2 = in.nextInt();

int radie3 = in.nextInt();

int totarea = area(radie1)+ area(radie2)+ area(radie3);

System.out.println(totarea);

}

private static int area(int radie){

return (int) (Math.PI * radie * radie);

}

}