#include <bits/stdc++.h>
#define fr first
#define sc second
#define all(a) (a).begin(), (a).end()
#define unique(a) a.resize(unique(a.begin(), a.end()) - a.begin())

using namespace std;

#ifdef ONPC
mt19937 rnd(223);
#else
mt19937 rnd(chrono::high_resolution_clock::now()
			.time_since_epoch().count());
#endif

#define TIME (clock() * 1.0 / CLOCKS_PER_SEC)

using ll = long long;
using ld = double;

const int maxn = 5e5 + 100, inf = 1e9 + 100;

void slow() {
    const int BIG = 1e9;
    const ll INF = 1e12;
    const int N = 5;
    const int X = 100;

    mt19937 rnd(239);
    for (int test = 0; test < 1000; test++) {
        int n = rnd() % N + 1;
        vector<int> h(n);
        for (int i = 0; i < n; i++) {
            h[i] = rnd() % X + 1;
        }
        vector<vector<pair<int, int>>> dp(n, vector<pair<int, int>>(2, make_pair(-BIG, BIG)));
        for (int i = 1; i < n; i++) {
            for (int bit = 0; bit < 2; bit++) {
                vector<pair<int, int>> segs;
                if (bit == 0 && h[i - 1] < h[i]) {
                    segs.emplace_back(dp[i - 1][bit]);
                } else if (bit == 1 && h[i - 1] > h[i]) {
                    segs.emplace_back(dp[i - 1][bit]);
                }
                if (bit == 0) {
                    auto seg = dp[i - 1][bit ^ 1];
                    seg.second = min(seg.second, h[i] + h[i - 1]);
                    if (seg.second >= seg.first) {
                        segs.emplace_back(seg);
                    }
                } else {
                    auto seg = dp[i - 1][bit ^ 1];
                    seg.first = max(seg.first, h[i] + h[i - 1]);
                    if (seg.second >= seg.first) {
                        segs.emplace_back(seg);
                    }
                }
                if (segs.empty()) {
                    dp[i][bit] = make_pair(0, -1);
                } else if (segs.size() == 1) {
                    dp[i][bit] = segs[0];
                } else {
                    if (segs[0] > segs[1]) {
                        swap(segs[0], segs[1]);
                    }
                    if (segs[0].second + 1 < segs[1].first) {
                        cout << n << "\n";
                        for (int x : h) {
                            cout << x << " ";
                        }
                        cout << "\n";
                        exit(0);
                    }
                    assert(segs[0].second + 1 >= segs[1].first);
                    dp[i][bit] = make_pair(min(segs[0].first, segs[1].first), max(segs[0].second, segs[1].second));
                }
            }
        }
    }

}

namespace segtree {

// This implementation is disgusting, but it seems to work and do it faster than previous version.

    template<typename Item>
    Item tree_merge(const Item& a, const Item& b) {
        Item i;
        i.update(a, b);
        return i;
    }

    template<typename Item, bool lazy>
    struct Pusher {};

    template<typename Item>
    struct Pusher<Item, false> {
        void push(const vector<Item>&, int, int, int) {}
        Item ask_on_segment(const vector<Item>& tree, int n, int l, int r) {
            l |= n;
            r |= n;
            Item resl, resr;
            while (l <= r) {
                if (l & 1) {
                    resl = tree_merge(resl, tree[l]);
                    ++l;
                }
                if (!(r & 1)) {
                    resr = tree_merge(tree[r], resr);
                    --r;
                }
                l >>= 1;
                r >>= 1;
            }
            return tree_merge(resl, resr);
        }
        void push_point(const vector<Item>&, int, int) {}

        template<typename P>
        int lower_bound(const vector<Item>& tree, int n, int l, P p) {
            Item cur;
            if (p(cur)) return l - 1;
            l |= n;
            int r = n | (n - 1);
            // carefully go up
            while (true) {
                if (p(tree_merge(cur, tree[l]))) {
                    break;
                }
                if (l == r) return n;
                if (l & 1) {
                    cur = tree_merge(cur, tree[l]);
                    ++l;
                }
                l >>= 1;
                r >>= 1;
            }

            // usual descent from l
            while (l < n) {
                if (p(tree_merge(cur, tree[l * 2]))) {
                    l = l * 2;
                } else {
                    cur = tree_merge(cur, tree[l * 2]);
                    l = l * 2 + 1;
                }
            }
            return (l ^ n);
        }

        template<typename P>
        int lower_bound_rev(const vector<Item>& tree, int n, int r, P p) {
            Item cur;
            if (p(cur)) return r + 1;
            r |= n;
            int l = n;
            // carefully go up
            while (true) {
                if (p(tree_merge(tree[r], cur))) {
                    break;
                }
                if (l == r) return -1;
                if (!(r & 1)) {
                    cur = tree_merge(tree[r], cur);
                    --r;
                }
                l >>= 1;
                r >>= 1;
            }

            // usual descent from r
            while (r < n) {
                if (p(tree_merge(tree[r * 2 + 1], cur))) {
                    r = r * 2 + 1;
                } else {
                    cur = tree_merge(tree[r * 2 + 1], cur);
                    r = r * 2;
                }
            }
            return (r ^ n);
        }
    };

    template<typename Item>
    struct Pusher<Item, true> {
        void push(vector<Item>& tree, int ind, int l, int r) {
            tree[ind].push(tree[ind * 2], tree[ind * 2 + 1], l, r);
        }

        Item ask_on_segment(vector<Item>& tree, int n, int l, int r) {
            int vl = 0, vr = n - 1;
            int i = 1;
            Item result;
            while (vl != vr) {
                int m = (vl + vr) / 2;
                if (l > m) {
                    push(tree, i, vl, vr);
                    i = i * 2 + 1;
                    vl = m + 1;
                } else if (r <= m) {
                    push(tree, i, vl, vr);
                    i = i * 2;
                    vr = m;
                } else {
                    break;
                }
            }
            if (l == vl && r == vr) {
                return tree[i];
            }
            push(tree, i, vl, vr);
            // left
            {
                int ind = i * 2;
                int L = vl, R = (vl + vr) / 2;
                while (l != L) {
                    int m = (L + R) / 2;
                    push(tree, ind, L, R);
                    if (l <= m) {
                        result = tree_merge(tree[ind * 2 + 1], result);
                        ind *= 2;
                        R = m;
                    } else {
                        ind = ind * 2 + 1;
                        L = m + 1;
                    }
                }
                result = tree_merge(tree[ind], result);
            }
            // right
            {
                int ind = i * 2 + 1;
                int L = (vl + vr) / 2 + 1, R = vr;
                while (r != R) {
                    int m = (L + R) / 2;
                    push(tree, ind, L, R);
                    if (r > m) {
                        result = tree_merge(result, tree[ind * 2]);
                        ind = ind * 2 + 1;
                        L = m + 1;
                    } else {
                        ind = ind * 2;
                        R = m;
                    }
                }
                result = tree_merge(result, tree[ind]);
            }
            return result;
        }

        void push_point(vector<Item>& tree, int n, int ind) {
            int l = 0, r = n - 1;
            int i = 1;
            while (l != r) {
                push(tree, i, l, r);
                int m = (l + r) / 2;
                if (ind <= m) {
                    r = m;
                    i *= 2;
                } else {
                    l = m + 1;
                    i = i * 2 + 1;
                }
            }
        }

        template<typename P>
        pair<int, Item> _lower_bound(vector<Item>& tree, int l, P p, Item cur, int i, int vl, int vr) {
            if (vl == vr) {
                if (p(tree_merge(cur, tree[i]))) {
                    return {vl, tree[i]};
                } else {
                    return {vl + 1, tree[i]};
                }
            }

            push(tree, i, vl, vr);
            int m = (vl + vr) / 2;
            if (l > m) {
                return _lower_bound(tree, l, p, cur, i * 2 + 1, m + 1, vr);
            } else if (l <= vl) {
                if (!p(tree_merge(cur, tree[i]))) {
                    return {vr + 1, tree_merge(cur, tree[i])};
                }
                if (p(tree_merge(cur, tree[i * 2]))) {
                    return _lower_bound(tree, l, p, cur, i * 2, vl, m);
                } else {
                    return _lower_bound(tree, l, p, tree_merge(cur, tree[i * 2]), i * 2 + 1, m + 1, vr);
                }
            } else {
                auto [ind, it] = _lower_bound(tree, l, p, cur, i * 2, vl, m);
                if (ind <= m) return {ind, it};
                return _lower_bound(tree, l, p, it, i * 2 + 1, m + 1, vr);
            }
        }

        template<typename P>
        int lower_bound(vector<Item>& tree, int n, int l, P p) {
            Item cur;
            if (p(cur)) return l - 1;
            return _lower_bound(tree, l, p, cur, 1, 0, n - 1).first;
        }

        template<typename P>
        pair<int, Item> _lower_bound_rev(vector<Item>& tree, int r, P p, Item cur, int i, int vl, int vr) {
            if (vl == vr) {
                if (p(tree_merge(tree[i], cur))) {
                    return {vl, tree[i]};
                } else {
                    return {vl - 1, tree[i]};
                }
            }

            push(tree, i, vl, vr);
            int m = (vl + vr) / 2;
            if (r <= m) {
                return _lower_bound_rev(tree, r, p, cur, i * 2, vl, m);
            } else if (r >= vr) {
                if (!p(tree_merge(tree[i], cur))) {
                    return {vl - 1, tree_merge(cur, tree[i])};
                }
                if (p(tree_merge(tree[i * 2 + 1], cur))) {
                    return _lower_bound_rev(tree, r, p, cur, i * 2 + 1, m + 1, vr);
                } else {
                    return _lower_bound_rev(tree, r, p, tree_merge(tree[i * 2 + 1], cur), i * 2, vl, m);
                }
            } else {
                auto [ind, it] = _lower_bound_rev(tree, r, p, cur, i * 2 + 1, m + 1, vr);
                if (ind > m) return {ind, it};
                return _lower_bound_rev(tree, r, p, it, i * 2, vl, m);
            }
        }

        template<typename P>
        int lower_bound_rev(vector<Item>& tree, int n, int r, P p) {
            Item cur;
            if (p(cur)) return r + 1;
            return _lower_bound_rev(tree, r, p, cur, 1, 0, n - 1).first;
        }
    };

    template<typename Item, bool lazy = false>
    struct Segtree {
        vector<Item> tree;
        Pusher<Item, lazy> pusher;
        int n;
        int n0;

        Segtree(int n = 0) {
            build(n);
        }

        template<typename U>
        Segtree(const vector<U>& v) {
            build(v);
        }

        void build(int n) {
            this->n0 = n;
            while (n & (n - 1)) ++n;
            this->n = n;
            tree.assign(n * 2, {});
        }

        template<typename U>
        void build(const vector<U>& v) {
            build(v.size());
            for (int i = 0; i < v.size(); ++i) {
                tree[n | i].init(v[i], i);
            }
            build();
        }

        void build() {
            for (int i = n - 1; i >= 1; --i) {
                tree[i].update(tree[i * 2], tree[i * 2 + 1]);
            }
        }

        void push(int ind, int l, int r) {
            pusher.push(tree, ind, l, r);
        }

        template<typename T>
        void set(int ind, const T& t) {
            pusher.push_point(tree, n, ind);
            ind |= n;
            tree[ind].init(t, ind ^ n);
            ind >>= 1;
            while (ind) {
                tree[ind].update(tree[ind * 2], tree[ind * 2 + 1]);
                ind >>= 1;
            }
        }

        template<typename T>
        void update(int ind, const T& t) {
            pusher.push_point(tree, n, ind);
            ind |= n;
            tree[ind].update(t, ind ^ n);
            ind >>= 1;
            while (ind) {
                tree[ind].update(tree[ind * 2], tree[ind * 2 + 1]);
                ind >>= 1;
            }
        }

        Item& ith(int ind) {
            static_assert(!lazy, "don't use this method with lazy propagation, unless you're sure you need it");
            return tree[ind | n];
        }

        const Item& root() const {
            return tree[1];
        }

        Item ask(int l, int r) {
            l = max(l, 0);
            r = min(r, n - 1);
            if (l > r) return {};
            return pusher.ask_on_segment(tree, n, l, r);
        }

        template<typename T>
        void modify(int l, int r, const T& t) {
            static_assert(lazy, "lazy must be set to true to use this function");
            l = max(l, 0);
            r = min(r, n - 1);
            if (l > r) return;
            int vl = 0, vr = n - 1;
            int i = 1;
            while (vl != vr) {
                int m = (vl + vr) / 2;
                if (l > m) {
                    push(i, vl, vr);
                    i = i * 2 + 1;
                    vl = m + 1;
                } else if (r <= m) {
                    push(i, vl, vr);
                    i = i * 2;
                    vr = m;
                } else {
                    break;
                }
            }
            if (l == vl && r == vr) {
                tree[i].modify(t, l, r);
            } else {
                push(i, vl, vr);
                // left
                {
                    int ind = i * 2;
                    int L = vl, R = (vl + vr) / 2;
                    while (l != L) {
                        int m = (L + R) / 2;
                        push(ind, L, R);
                        if (l <= m) {
                            tree[ind * 2 + 1].modify(t, m + 1, R);
                            ind *= 2;
                            R = m;
                        } else {
                            ind = ind * 2 + 1;
                            L = m + 1;
                        }
                    }
                    tree[ind].modify(t, L, R);
                    ind >>= 1;
                    while (ind != i) {
                        tree[ind].update(tree[ind * 2], tree[ind * 2 + 1]);
                        ind >>= 1;
                    }
                }
                // right
                {
                    int ind = i * 2 + 1;
                    int L = (vl + vr) / 2 + 1, R = vr;
                    while (r != R) {
                        int m = (L + R) / 2;
                        push(ind, L, R);
                        if (r > m) {
                            tree[ind * 2].modify(t, L, m);
                            ind = ind * 2 + 1;
                            L = m + 1;
                        } else {
                            ind = ind * 2;
                            R = m;
                        }
                    }
                    tree[ind].modify(t, L, R);
                    ind >>= 1;
                    while (ind != i) {
                        tree[ind].update(tree[ind * 2], tree[ind * 2 + 1]);
                        ind >>= 1;
                    }
                }
                tree[i].update(tree[i * 2], tree[i * 2 + 1]);
            }
            i >>= 1;
            while (i) {
                tree[i].update(tree[i * 2], tree[i * 2 + 1]);
                i >>= 1;
            }
        }

        // first index r such that p(tree.ask(l, r)) == true
        // if p() is true for empty item, return l-1
        // if p() is never true, returns n
        template<typename P>
        int lower_bound(int l, P p) {
            l = max(l, 0);
            if (l >= n0) return n0;
            return min(n0, pusher.lower_bound(tree, n, l, p));
        }

        // similarly to lower_bound, returns first (largest) l such that p(tree.ask(l, r)) == true
        template<typename P>
        int lower_bound_rev(int r, P p) {
            r = min(r, n0 - 1);
            if (r < 0) return -1;
            return pusher.lower_bound_rev(tree, n, r, p);
        }
    };

}
using segtree::Segtree;

struct Item {
    bool d[2][2];

    Item() {
        d[0][0] = d[1][1] = 1;
        d[0][1] = d[1][0] = 0;
    }

    template<typename T>
    void init(const T& t, int ind) {
        d[0][0] = d[1][1] = 1;
        d[0][1] = d[1][0] = 0;
    }

    void update(const Item& a, const Item& b) {
        memset(d, 0, sizeof(d));
        for (int i = 0; i < 2; i++)
            for (int j = 0; j < 2; j++)
                if (a.d[i][j])
                for (int k = 0; k < 2; k++)
                    if (b.d[j][k])
                        d[i][k] = 1;
    }

    //// similar to init, but more convenient for doing a[i] += x, implement only if needed
     template<typename T>
     void update(const T& t, int ind) {
         d[t.fr.fr][t.fr.sc] = t.sc;
     }

    //// apply here, save for children
    // template<typename T>
    // void modify(const T& m, int l, int r) {}

    // void push(Item& a, Item& b, int l, int r) {
    //     int m = (l + r) / 2;
    //     a.modify(mod, l, m);
    //     b.modify(mod, m + 1, r);
    //     // reset mod
    // }
};

/*

         // first index r such that p(tree.ask(l, r)) == true
        // if p() is true for empty item, return l-1
        // if p() is never true, returns n
        template<typename P>
        int lower_bound(int l, P p) {
            l = max(l, 0);
            if (l >= n0) return n0;
            return min(n0, pusher.lower_bound(tree, n, l, p));
        }

        // similarly to lower_bound, returns first (largest) l such that p(tree.ask(l, r)) == true
        template<typename P>
        int lower_bound_rev(int r, P p) {
            r = min(r, n0 - 1);
            if (r < 0) return -1;
            return pusher.lower_bound_rev(tree, n, r, p);
        }

 */

#define cerr if(0)cerr
#define cin if(0)cin
void solve() {
    int n;
    n = 5e5;
    cin >> n;
    vector<ll> a(n);
    for (ll &i : a) {
        i = rnd() % int(1e9) + 1;
        cin >> i;
    }
    vector<pair<ll, int>> g;
    Segtree<Item> t(n);
    auto dai = [&](int x, int y, int w) {
        return make_pair(make_pair(x, y), w);
    };
    for (int i = 0; i + 1 < n; i++) {
        if (a[i] < a[i + 1]); else
            t.update(i, dai(0, 0, 0));
        if (a[i] > a[i + 1]); else
            t.update(i, dai(1, 1, 0));
        g.push_back({a[i] + a[i + 1], i});
        t.update(i, dai(1, 0, 1));
    }
    sort(all(g));
    vector<pair<int, int>> che;
    auto pred = [&](Item const &w) -> bool {
        for (int i = 0; i < 2; i++)
            for (int j = 0; j < 2; j++)
                if (w.d[i][j])
                    return 0;
        return 1;
    };
    auto print = [&]() {
        return;
        for (int i = 0; i < n - 1; i++) {
            auto w = t.ask(i, i);
            for (int x = 0; x < 2; x++)
                for (int y = 0; y < 2; y++)
                    cerr << w.d[x][y];
            cerr << ' ';
        }
        cerr << '\n';
    };
    print();
    for (int i = 0; i < n; i++) {
        int r = t.lower_bound(i, pred);
        r--;
        if (r > i) {
            cerr << "i " << i << ' ' << r << '\n';
            che.push_back({i, r});
        }
    }
    int L = 0;
    while (L < g.size()) {
        int R = L;
        vector<int> pos;
        while (R < g.size() && g[R].fr == g[L].fr) {
            int i = g[R].sc;
            R++;
            t.update(i, dai(0, 1, 1));
            t.update(i, dai(1, 0, 0));
            pos.push_back(i);
        }
        cerr << "done " << g[L].fr << '\n';
        L = R;
        print();
        {
            // edge 0->1
            for (int i : pos) {
                auto p2 = [&](Item const &w) -> bool {
                    return w.d[1][0] == 0 && w.d[1][1] == 0;
                };
                auto p1 = [&](Item const &w) -> bool {
                    return w.d[0][0] == 0 && w.d[1][0] == 0;
                };
                int r = t.lower_bound(i + 1, p2);
                int l = t.lower_bound_rev(i - 1, p1);
                l++;
                if (l < r) {
                    cerr << "ad " << l << ' ' << r << '\n';
                    che.push_back({l, r});
                }
            }
        }
    }
    vector<vector<int>> op(n);
    vector<vector<int>> cl(n);
    for (auto [l, r] : che) {
        l = max(0, l);
        r = min(n - 1, r);
        if (l >= r)
            continue;
        op[l].push_back(r);
        cl[r].push_back(r);
    }
    multiset<int> q;
    ll ans = 0;
    for (int i = 0; i < n; i++) {
        for (int w : op[i])
            q.insert(w);
        if (!q.empty()) {
            int r = *q.rbegin();
            ans += r - i;
        }
        for (int w : cl[i])
            q.erase(q.find(w));
    }
    cout << ans << '\n';
}

int main() {
#ifdef ONPC
    freopen("../a.in", "r", stdin);
//    freopen("../a.out", "w", stdout);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout << fixed;
    cout.precision(20);
    solve();
    cout << "\n\nConsumed " << TIME << endl;
}

/*
C:\Users\ramil\Desktop\trenirovka\waterloo\ucups\2nd\tmp\cmake-build-debug\tmp.exe
1000 0001 1000
4
i 2 3
done 4
1100 0001 1000
ad 0 2
done 5
1100 0101 1000
ad 0 2
done 6
1100 0101 1100
ad 2 4


Consumed 0.015

Process finished with exit code 0

 */