#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pi;
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define REP(i,a,b) for (int i=a;i<=b;i++)
#define PER(i,a,b) for (int i=a;i>=b;i--)

pair<ll,int> solve(int k, vector<int> a) {
	if (k==1) return (make_pair(max(a[0], a[1])*2, max(a[0], a[1])));
	vector<int> left;
	vector<int> right;
	int step = 2;
	int i = 2;
	while (step < (1<<k)) {
		for (int j=1; j<=step; j++) {
			left.push_back(a[i]);
			i++;
	 	}
	 	for (int j=1; j<=step; j++) {
			right.push_back(a[i]);
			i++;
	 	}
	 	step=step*2;
	}
//	cout<<left.size()<<' ';
//	cout<<right.size()<<endl;
//	cout<<"WTF"<<endl;
	pair<ll,int> ans_left, ans_right;
	ans_left = solve(k-1, left);
	ans_right = solve(k-1, right);
	pair<ll,int> ans;
	int x = max(a[0] + ans_left.S, a[1] + ans_right.S);
	ans.F = ans_left.F + ans_right.F + x - ans_left.S + x - ans_right.S;
	ans.S = x;
	return(ans);
}

int main()
	{
	ios::sync_with_stdio(0);
	cin.tie(0);

	int k;
	cin>>k;
	int e;
	e = (1<<(k+1))-2;
	vector<int> a;
	for (int i=0; i<e; i++) {
		int c;
		cin>>c;
		a.push_back(c);
	}

	cout<<solve(k, a).F;





return 0;
}