acm2013

/**

* 蟠桃记

* 每天吃掉桃子总数一半多一个

*/

import java.util.*;

public class acm2013 {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

while(in.hasNextInt()){

int day = in.nextInt();

int sum = 1;

for(int i = 1 ; i<day ;i++){

sum = (sum + 1) * 2;

}

System.out.println(sum);

}

}

}