View Code of Problem 73

import java.util.Scanner;
 
public class Main 
{
 
	public static void main(String[] args) 
        {
          Scanner scan=new Scanner(System.in);
          int n=scan.nextInt();
          int sum=1;
          for(int i=1;i<n;i++)
          {
            sum=(sum+1)*2;
          }
          System.out.print(sum);
        }
}