import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	}
		

} import java.math.BigDecimal; BigDecimal java.math import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	}
		

} Main public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	} main {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	} try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		} {
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		} Scanner scan = new Scanner(System.in) Scanner scan = new Scanner(System.in) new Scanner(System.in) int L = scan.nextInt(); L scan.nextInt() scan.nextInt scan double tate =0; tate 0 double yoko = 0; yoko 0 double takasa = 0; takasa 0 if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			} L%3==0 L%3 L 3 0 {
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			} tate = (double)L/3 tate (double)L/3 (double)L 3 yoko = (double)L/3 yoko (double)L/3 (double)L 3 takasa = (double)L/3 takasa (double)L/3 (double)L 3 double X = tate*yoko*takasa; X tate*yoko*takasa tate*yoko*takasa tate yoko takasa String str = BigDecimal.valueOf(X).toPlainString(); str BigDecimal.valueOf(X).toPlainString() BigDecimal.valueOf(X).toPlainString BigDecimal.valueOf(X) BigDecimal.valueOf BigDecimal X System.out.println(str) System.out.println System.out System System.out str {
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			} double amari = (double)L%3.0/3.0; amari (double)L%3.0/3.0 (double)L%3.0 (double)L 3.0 3.0 tate = (double)(L/3)+amari tate (double)(L/3)+amari (double)(L/3) L 3 amari yoko = (double)(L/3)+amari yoko (double)(L/3)+amari (double)(L/3) L 3 amari takasa = (double)(L/3)+amari takasa (double)(L/3)+amari (double)(L/3) L 3 amari double X = tate*yoko*takasa; X tate*yoko*takasa tate*yoko*takasa tate yoko takasa String str = BigDecimal.valueOf(X).toPlainString(); str BigDecimal.valueOf(X).toPlainString() BigDecimal.valueOf(X).toPlainString BigDecimal.valueOf(X) BigDecimal.valueOf BigDecimal X System.out.println(str) System.out.println System.out System System.out str String[]args args public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	}
		

} public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	}
		

} Main
import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
	public static void main(String[]args) {
		try(Scanner scan = new Scanner(System.in)){
			
			int L = scan.nextInt();//Lは１０００まで
			double tate =0;
			double yoko = 0;
			double takasa = 0;
			
			
			if(L%3==0){
				tate = (double)L/3;
				yoko = (double)L/3;
				takasa = (double)L/3;
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);	
			}else{
				double amari = (double)L%3.0/3.0;
				tate = (double)(L/3)+amari;
				yoko = (double)(L/3)+amari;
				takasa = (double)(L/3)+amari;
				
				double X = tate*yoko*takasa;
				String str = BigDecimal.valueOf(X).toPlainString();
				System.out.println(str);
				
				//System.out.println(amari);
				//System.out.println(L/3.0);
				
				
			}
			
		}
		
		
	}
		

}
