// clang-format off
#include <iostream>
#include <iomanip>
#include <fstream>
#include <sstream>
#include <string>

#include <algorithm>
#include <numeric>
#include <limits>
#include <chrono>
#include <functional>
#include <iterator>
#include <random>
#include <complex>
#include <utility>
#include <type_traits>
#include <tuple>
#include <memory>

#include <vector>
#include <array>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <set>
#include <valarray>

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <csignal>
#include <cstdint>
#include <cstddef>

#ifdef ONLINE_JUDGE
#define NDEBUG
#endif
#include <cassert>
#include <stdexcept>
#include <exception>

// << pair
template <typename T1, typename T2>std::ostream&operator<<(std::ostream&os,const std::pair<T1,T2>&p){return os<<"("<<p.first<<", "<<p.second<<")";}
// << container
template<typename,template<typename...> class...>struct is_instantiation_of:public std::false_type{};
template<template<typename...>class U,template<typename...>class...Us,typename...T>struct is_instantiation_of<U<T...>,U,Us...>:public std::true_type{};
template<typename S,template<typename...>class U,template<typename...>class...Us>struct is_instantiation_of<S,U,Us...>:std::integral_constant<bool,is_instantiation_of<S,Us...>::value>{};

template<typename C>std::ostream&_debug_go(std::ostream&,const C&);
template<typename C,typename=std::enable_if_t<is_instantiation_of<C,std::vector,std::deque,std::set,std::map,std::unordered_set,std::unordered_map,std::multiset,std::multimap,std::unordered_multiset,std::unordered_multimap,std::valarray>::value>>std::ostream&operator<<(std::ostream&os,const C&v){return _debug_go(os,v);}
template<typename T,std::size_t N> std::ostream& operator<<(std::ostream&os,const std::array<T,N>&v){return _debug_go(os,v);}
template<typename C>std::ostream& _debug_go(std::ostream&os,const C& v){bool first=true;os<<"[";for(auto i:v){if(!first)os<<", ";else first=false;os<<i;}return os<<"]";}

struct Debugger{template<typename T>Debugger&operator,(const T&v){std::cerr<<v<<" ";return *this;}} dbg;
#ifndef NDEBUG
#define debug(args...) do {dbg,args; cerr << "\n";} while(0)
#else
#define debug(args...)
#endif

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define ITER(i, s, e) for (auto i((s)); i != (e); ++i)
#define IT(i, c) ITER(i, (c).begin(), (c).end())

using namespace std;

using ui = uint32_t;
using ll = int64_t;
using ull = uint64_t;
template <typename T = int> using Pt = complex<T>;

template <typename T>
T cross(const Pt<T>& a, const Pt<T>& b) { return a.real() * b.imag() - a.imag() * b.real(); }

template <typename T>
bool cmpPt(const Pt<T>& a, const Pt<T>& b) {
  return a.real() < b.real() || (a.real() == b.real() && a.imag() < b.imag());
}
// END TEMPLATE
// clang-format on

ll numRange(const vector<int>& l, int i, const vector<int>& r) {
  return 1LL * (i - l[1]) * (r[1] - r[0]) + 1LL * (l[1] - l[0]) * (r[0] - i);
}

ll solve(int N, const vector<int>& P) {
  vector<int> pos(N);
  REP(i, N) pos[P[i]] = i;
  set<int> ix;
  ll ans = 0;
  for (int i = N - 1; i >= 0; --i) {
    auto it = ix.lower_bound(pos[i]);
    auto rit = it;
    auto lit = reverse_iterator<decltype(rit)>(rit);
    vector<int> l, r;
    REP(_, 2) {
      if (rit == ix.end()) break;
      r.push_back(*rit++);
    }
    while (r.size() < 2) r.push_back(N);
    REP(_, 2) {
      if (lit == ix.rend()) break;
      l.push_back(*lit++);
    }
    while (l.size() < 2) l.push_back(-1);
    reverse(l.begin(), l.end());
    ans += i * numRange(l, pos[i], r);
    ix.insert(pos[i]);
  }
  return ans;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  int N;
  cin >> N;
  vector<int> P(N);
  for (int& p : P) cin >> p, --p;
  cout << solve(N, P) + 1LL * N * (N - 1) / 2 << '\n';

  return 0;
}


Measured memory_bytes: 5760