//#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i=0; i<n; ++i)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
using ll = int64_t;
using ull = uint64_t;
using ld = long double;
using P = pair<int, int>;
using vs = vector<string>;
using vi = vector<int>;
using vvi = vector<vi>;
template<class T> using PQ = priority_queue<T>;
template<class T> using PQG = priority_queue<T, vector<T>, greater<T>>;
const int INF = 0xccccccc;
const ll LINF = 0xcccccccccccccccLL;
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 T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) { return is >> p.first >> p.second;}
template<typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) { return os << p.first << ' ' << p.second;}

template<class T>
struct SWAG {
  using FX = function<T(T, T)>;
  stack<pair<T, T>> frst, bcst;
  FX fx;
  const T ex;
  //fx(新, 古)
  SWAG(FX fx_, T ex_):fx(fx_), ex(ex_) {}
  void push(T x) {
    bcst.emplace(x, fx(x, (bcst.empty()?ex:bcst.top().second)));
  }
  void pop() {
    if(frst.empty()) {
      while(!bcst.empty()) {
        frst.emplace(bcst.top().first, fx((frst.empty()?ex:frst.top().second), bcst.top().first));
        bcst.pop();
      }
    }
    assert(!frst.empty());
    frst.pop();
  }
  T calc() {
    return fx(bcst.empty()?ex:bcst.top().second, frst.empty()?ex:frst.top().second);
  }
};

struct S {
  int m1, m2, M;
  int calc() {return m1+m2-M;}
};

//head



int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  vi a(n);
  rep(i, n) cin >> a[i];
  auto fx = [](S a, S b)->S {
    if(a.m1 > b.m1) swap(a, b);
    return {a.m1, min(a.m2, b.m1), max(a.M, b.M)};
  };
  SWAG<S> s(fx, S({INT_MAX/2, INT_MAX/2, 0}));
  ll ans = 0;
  int j = 0;
  rep(i, n-1) {
    while(j < n and s.calc().calc() >= 0) {
      s.push({a[j], INT_MAX/2, a[j]});
      j++;
    }
    ans += j-i-2+(s.calc().calc() >= 0);
    s.pop();
  }
  cout << ans << endl;
}