// #define LOCAL
#define _USE_MATH_DEFINES
#include <array>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>
#include <functional>
#include <random>
#include <ctime>

using namespace std;

template <typename A, typename B>
ostream& operator <<(ostream& out, const pair<A, B>& a) {
  out << "(" << a.first << "," << a.second << ")";
  return out;
}
template <typename T, size_t N>
ostream& operator <<(ostream& out, const array<T, N>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const vector<T>& a) {
  out << "["; bool first = true;
  for (auto v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const set<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator <<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& p : a) { out << (first ? "" : ", "); out << p.first << ":" << p.second; first = 0;} out << "}";
  return out;
}
#ifdef LOCAL
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
#else
#define trace(...) 42
#endif
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

template <class T> auto vect(const T& v, int n) { return vector<T>(n, v); }
template <class T, class... D> auto vect(const T& v, int n, D... m) {
  return vector<decltype(vect(v, m...))>(n, vect(v, m...));
}

typedef long long int64;
typedef pair<int, int> ii;
#define SZ(x) (int)((x).size())
template <typename T> static constexpr T inf = numeric_limits<T>::max() / 2;
const int MOD = 1e9 + 7;
// const int MOD = 998244353;
mt19937 mrand(random_device{}());
int rnd(int x) { return mrand() % x; }
// mt19937_64 mrand(random_device{}());
// int64 rnd(int64 x) { return mrand() % x; }
template <class T> void out(const vector<T>& a) { for (int i = 0; i < SZ(a); ++i) cout << a[i] << " \n"[i + 1 == SZ(a)]; }
template <class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template <class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
template <class T> void dedup(vector<T>& v) { sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end()); }
void add(int& x, int y) { x += y; if (x >= MOD) x -= MOD; }

struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
  };
} fast_ios_;

int main() {
  int n;
  cin >> n;
  vector<int> a(n);
  for (auto& x : a) cin >> x;

  const int N = 2e5 + 10;
  vector<int> lg2(N);
  for (int k = 2; k < N; ++k) lg2[k] = lg2[k / 2] + 1;

  const int K = 20;
  auto mn = vect<ii>({0, 0}, n, K);
  for (int i = 0; i < n; ++i) mn[i][0] = {a[i], inf<int>};
  auto merge =
    [&](const ii& L, const ii& R) {
      vector<int> a = {L.first, L.second, R.first, R.second};
      sort(a.begin(), a.end());
      return ii{a[0], a[1]};
    };
  for (int k = 1; k < K; ++k) {
    for (int i = 0; i + (1 << k) <= n; ++i) {
      auto L = mn[i][k - 1];
      int j = i + (1 << (k - 1));
      auto R = mn[j][k - 1];
      mn[i][k] = merge(L, R);
    }
  }
  auto mx = vect<int>(0, n, K);
  for (int i = 0; i < n; ++i) mx[i][0] = a[i];
  for (int k = 1; k < K; ++k) {
    for (int i = 0; i + (1 << k) <= n; ++i) {
      int j = i + (1 << (k - 1));
      mx[i][k] = max(mx[i][k - 1], mx[j][k - 1]);
    }
  }
  auto get_max =
    [&](int x, int y) {
      int k = lg2[y - x + 1];
      return max(mx[x][k], mx[y - (1 << k) + 1][k]);
    };
  auto get_min =
    [&](int x, int y) {
      ii best = {inf<int>, inf<int>};
      while (x <= y) {
        int k = lg2[y - x + 1];
        best = merge(best, mn[x][k]);
        x += 1 << k;
      }
      return best;
    };
  int64 ret = 0;
  for (int i = 0; i < n - 1; ++i) {
    int low = i + 1, high = n - 1;
    while (low != high) {
      int mid = (low + high + 1) / 2;
      auto p = get_min(i, mid);
      auto q = get_max(i, mid);
      if (i == 2 && mid == 4) trace(p, q);
      if (p.first + p.second < q) {
        high = mid - 1;
      } else {
        low = mid;
      }
    }
    trace(i, high);
    ret += high - i;
  }
  cout << ret << '\n';
  return 0;
}