#include<bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 1e9 + 7;
// const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;


template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in : v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e : t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

using LL = int64;

int main() {
  int N;
  cin >> N;
  vector< LL > val(N, 0);
  vector< vector< int > > child(N, vector< int >());
  cin >> val[0];
  if(N == 1) {
    cout << 0 << endl;
    return 0;
  }
  val[0] *= -1;
  LL sum = -val[0];
  for(int i = 1; i < N; i++) {
    LL c;
    cin >> c;
    c *= -1;
    LL p = i - 1;
    val[i] = c;
    child[p].push_back(i);
    sum -= val[i];
  }
  vector< priority_queue< LL > > qu;
  vector< int > ind(N, 0);
  int itr = 0;
  for(int i = N - 1; i >= 0; i--) {
    if(child[i].size() == 0 && i > 0) {
      priority_queue< LL > tmp;
      tmp.push(val[i]);
      qu.push_back(tmp);
      ind[i] = itr;
      itr++;
      sum += val[i];
      continue;
    }
    int cand = -1;
    int maxim = 0;

    for(auto v : child[i]) {
      if(maxim < qu[ind[v]].size()) {
        maxim = qu[ind[v]].size();
        cand = v;
      }
    }
    ind[i] = ind[cand];
    for(auto v: child[i]) {
      if(v == cand) continue;
      int from = ind[v];
      while(!qu[from].empty()) {
        qu[ind[i]].push(qu[from].top());
        qu[from].pop();
      }
    }
    qu[ind[i]].push(val[i]);
    qu[ind[i]].push(val[i]);
    sum += qu[ind[i]].top();
    qu[ind[i]].pop();

  }
  cout << sum << endl;
}