B. Om Nom and Dark Park

import java.util.Scanner;


public class B526 {

    private static void solve(){
        Scanner in=new Scanner(System.in);
        int n=in.nextInt();
        int l=(1<<(n+1));
        int[] a=new int[l];
        for(int i=2;i<a.length;++i){
            a[i]=in.nextInt();
        }
            int ans =0;
            for( int i=(1<<n)-1;i>=1;--i){
                ans+=Math.abs(a[2*i]-a[2*i+1]);
                a[i]+=Math.max(a[2*i], a[2*i+1]);
            }
            System.out.println(ans);
        }

    public static void main(String[] args) {
        new B526().solve();

    }

}