content: import java.io.*;
  import java.math.*;
  import java.security.*;
  import java.text.*;
  import java.util.*;
  import java.util.concurrent.*;
  import java.util.regex.*;
  
  public class Solution {
  
      //The initial people is 5 so 5 is assigned to variable p
      
      //variable sum is for the cumulative people who liked the advertisement
      
      static int viralAdvertising(int n) {
          int i,p=5,sum=0;
          
          //n is the number of days this continues from the launch day 1
          
          for(i=1;i<=n;i++)
          {
              //number of people liking the advt is floor( initial people/2)
              
              p=p/2;
              
              sum=sum+(p);
              
              //each person shares the advt with their 3 friends
              
              p=p*3;
          }
          return(sum);
      }
  
      private static final Scanner scanner = new Scanner(System.in);
  
      public static void main(String[] args) throws IOException {
          BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
  
          int n = scanner.nextInt();
          scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
          
          //calling the function viralAdvertising and passing no. of days 
          
          int result = viralAdvertising(n);
          
          //result stores the total number of people who liked the advt.
          
          bufferedWriter.write(String.valueOf(result));
          bufferedWriter.newLine();
  
          bufferedWriter.close();
  
          scanner.close();
      }
  }
  