//*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
//*/
 
#include <bits/stdc++.h>
 
// #include <atcoder/all>
 
using namespace std;
// using namespace atcoder;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
// #define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(int)(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
void YES(bool t=true) {cout<<(t?"YES":"NO")<<endl;}
void Yes(bool t=true) {cout<<(t?"Yes":"No")<<endl;}
void yes(bool t=true) {cout<<(t?"yes":"no")<<endl;}
void NO(bool t=true) {cout<<(t?"NO":"YES")<<endl;}
void No(bool t=true) {cout<<(t?"No":"Yes")<<endl;}
void no(bool t=true) {cout<<(t?"no":"yes")<<endl;}
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
int popcount(ll t) { return __builtin_popcountll(t); }
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {0, 1, 0, -1}, dy = {-1, 0, 1, 0};
// vi dx2 = { 1,1,0,-1,-1,-1,0,1 }, dy2 = { 0,1,1,1,0,-1,-1,-1 };
struct Setup_io {
    Setup_io() {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        cout << fixed << setprecision(25);
    }
} setup_io;
const ll MOD = 1000000007;
// const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'


template <typename T>
class SegmentTree {
public:
  using F = function<T(T&, T&)>;
  int n;
  vector<T > dat;
  T e; // �P�ʌ�
  F query_func;
  F update_func;
  
  SegmentTree(vector<T> a, F query_func, F update_func, T e) :n(a.size()), query_func(query_func), update_func(update_func), e(e) {
    if (n == 0) {
      a.push_back(e);
      n++;
    }
    dat.resize(4 * n);
    init(0, 0, n, a);
  }

  void init(int k, int l, int r, vector<T> &a) {
    if (r - l == 1) {
      dat[k] = a[l];
    }
    else {
      int lch = 2 * k + 1, rch = 2 * k + 2;
      init(lch, l, (l + r) / 2, a);
      init(rch, (l + r) / 2, r, a);
      dat[k] = query_func(dat[lch], dat[rch]);
    }
  }

  //k�Ԗڂ̒l��a�ɕύX
  void update(int k, T a, int v, int l, int r) {
    if (r - l == 1) {
      dat[v] = update_func(dat[v], a);
    }
    else {
      if (k < (l + r) / 2)
        update(k, a, 2 * v + 1, l, (l + r) / 2);
      else {
        update(k, a, 2 * v + 2, (l + r) / 2, r);
      }
      dat[v] = query_func(dat[v * 2 + 1], dat[v * 2 + 2]);
    }
  }
    

  //[a,b)�̍ŏ��l�����߂�
  //���̂ق��̈����͌v�Z�̊ȒP�̂��߂̈���
  //k�͐ړ_�̔ԍ�,l,r�͂��̐ړ_��[l,r)�ɑΉ����Ă��邱�Ƃ�\��
  //�]���āA�O�����query(a,b,0,0,n)�Ƃ��Ă��
  T query(int a, int b, int k, int l, int r) {
    if (r <= a || b <= l) {
      return e;
    }
    if (a <= l && r <= b) {
      return dat[k];
    }
    else {
      T ul = query(a, b, k * 2 + 1, l, (l + r) / 2);
      T ur = query(a, b, k * 2 + 2, (l + r) / 2, r);
      return query_func(ul, ur);
    }
  }

  // �����𖞂����ĉE��T��
  int find(int a, int b, int k, int l, int r, int x) {
    // �����𒼂�
    if (dat[k] < x || r <= a || b <= l) return -1;
    if (l + 1 == r) {
      // �����𒼂�
      if (dat[k] >= x) return l;
      else return -1;
    }
    int rv = find(a, b, 2 * k + 2, (l + r) / 2, r, x);
    if (rv != -1) return rv;
    return find(a, b, 2 * k + 1, l, (l + r) / 2, x);
  }
};

int f(int a, int b) {return a + b;}
int g(int a, int b) {return a + b;}

ll solve1(vi a) {
    int n = a.size();
    int rem;
    if (a[0] < a[1]) rem = 1;
    else rem = 0;

    vector<pii> ue;
    for (int i = rem; i < n; i += 2) {
        int side = -inf;
        if (i != 0) chmax(side, a[i - 1]);
        if (i != n - 1) chmax(side, a[i + 1]);
        ue.push_back(pii(a[i], side));
    }

    sort(all(ue));
    reverse(all(ue));
    vi num(n);
    rep (i, ue.size()) num[ue[i].first]++;

    SegmentTree<int> seg(num, f, g, 0);
    ll ans = 0;
    rep (i, ue.size()) {
        int x = ue[i].first;
        seg.update(x, -1, 0, 0, seg.n);
        int side = ue[i].second;
        ans += seg.query(side + 1, n, 0, 0, seg.n);
    }
    return ans;
}

ll solve2(vi a) {
    int n = a.size();
    int rem;
    if (a[0] < a[1]) rem = 1;
    else rem = 0;

    vector<pii> ue;
    for (int i = rem; i < n; i += 2) {
        int side = -inf;
        if (i != 0) chmax(side, a[i - 1]);
        if (i != n - 1) chmax(side, a[i + 1]);
        ue.push_back(pii(side, a[i]));
    }

    vector<pii> sita;
    for (int i = 1 - rem; i < n; i += 2) {
        int side = inf;
        if (i != 0) chmin(side, a[i - 1]);
        if (i != n - 1) chmin(side, a[i + 1]);
        sita.push_back(pii(a[i], side));
    }

    sort(all(ue));
    sort(all(sita));
    vi num(n);
    rep (i, sita.size()) num[sita[i].second]++;

    SegmentTree<int> seg(num, f, g, 0);
    int si = 0;
    ll ans = 0;
    rep (i, ue.size()) {
        int x = ue[i].first;
        while (si < sita.size() and sita[si].first <= x) {
            int val = sita[si].second;
            seg.update(val, -1, 0, 0, seg.n);
            si++;
        }

        int y = ue[i].second;
        ans += seg.query(y + 1, n, 0, 0, seg.n);
    }
    return ans;
}

signed main() {
    int n;
    cin >> n;
    vi a(n);
    rep (i, n) {
        cin >> a[i];
        a[i]--;
    }

    ll ans = solve1(a);
    vi b(n);
    rep (i, n) b[i] = n - 1 - a[i];
    ans += solve1(b);
    
    ans += solve2(a);
    cout << ans << endl;
}