杭电2013蟠桃记

import java.util.Scanner;public class Main{     public static void main(String[] args) {        Scanner sc = new Scanner(System.in);        while (sc.hasNext()) {            int tao = 1;            int N = sc.nextInt();            for (int i = 2; i <= N; i++) {                tao = (tao + 1) * 2;            }            System.out.println(tao);        }    }}