#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int MAX = 1e5 + 55;
const int INF = 1e9 + 77;
const long long INFINF = 1e18 + 1e17;
const double PI = acos(-1.0);
long long power(long long x, long long y) {
  if (y == 0) return 1;
  long long s = power(x, y / 2);
  s *= s;
  if (y & 1) s *= x;
  return s;
}
int n;
long long e[4000][4000];
long long dis[4000];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  int node = 1;
  for (int p = 1; p <= ((1 << n + 1) - 1) / 2; p++) {
    int dis1;
    int dis2;
    cin >> dis1;
    cin >> dis2;
    e[node * 2][node] = dis1;
    e[node * 2 + 1][node] = dis2;
    node++;
  }
  long long ans = 0;
  node = ((1 << n + 1) - 1);
  while (node != 1) {
    int node1 = node;
    int node2 = node - 1;
    int par = node / 2;
    int max1 = dis[node1] + e[node1][par];
    int max2 = dis[node2] + e[node2][par];
    dis[par] = max(max1, max2);
    ans += (dis[par] - min(max1, max2));
    node -= 2;
  }
  cout << ans;
  return 0;
}
