import java.util.*;
import java.math.BigDecimal;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    }
} import java.util.*; util.* java import java.math.BigDecimal; BigDecimal java.math public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    } main {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigDecimal L = new BigDecimal(sc.next()); L new BigDecimal(sc.next()) BigDecimal three = new BigDecimal("3"); three new BigDecimal("3") L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP) L L.divide(three, 6, BigDecimal.ROUND_HALF_UP) L.divide L three 6 BigDecimal.ROUND_HALF_UP BigDecimal BigDecimal.ROUND_HALF_UP System.out.println(L.multiply(L).multiply(L)) System.out.println System.out System System.out L.multiply(L).multiply(L) L.multiply(L).multiply L.multiply(L) L.multiply L L L String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    }
} Main
import java.util.*;
import java.math.BigDecimal;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        BigDecimal L = new BigDecimal(sc.next());
        BigDecimal three = new BigDecimal("3");
        
        L = L.divide(three, 6, BigDecimal.ROUND_HALF_UP);
        
        System.out.println(L.multiply(L).multiply(L));
    }
}