#include <bits/stdc++.h>
using namespace std;
const int N = 2300;
int dp[N], a[N], res = 0, n;
void dfs(int u, int d) {
  if (d == n) {
    dp[u] = 0;
    return;
  }
  int l = u * 2, r = l + 1;
  dfs(l, d + 1);
  dfs(r, d + 1);
  int x = dp[l] + a[l], y = dp[r] + a[r];
  if (x < y) swap(x, y);
  dp[u] = x;
  res += x - y;
}
int main() {
  cin >> n;
  for (int i = 2; i < (1 << n + 1); i++) {
    scanf("%d", &a[i]);
  }
  dfs(1, 0);
  cout << res << endl;
}
