import java.util.*;

public class Main{
public static void main(String[]args){
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
}

} import java.util.*; util.* java public class Main{
public static void main(String[]args){
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
}

} Main public static void main(String[]args){
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
} main {
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
} double a = 0.0; a 0.0 Scanner sc = new Scanner(System.in); sc new Scanner(System.in) a = sc.nextInt() a sc.nextInt() sc.nextInt sc double count =0.0; count 0.0 count=a*a*a/27.0 count a*a*a/27.0 a*a*a a*a*a a a a 27.0 System.out.println(count) System.out.println System.out System System.out count String[]args args public class Main{
public static void main(String[]args){
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
}

} public class Main{
public static void main(String[]args){
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
}

} Main
import java.util.*;

public class Main{
public static void main(String[]args){
    double a = 0.0;
    Scanner sc = new Scanner(System.in);
    a = sc.nextInt();
    double count =0.0;
    count=a*a*a/27.0;
    System.out.println(count);
}

}