#include <bits/stdc++.h>
#define For(i, a, b) for (int(i) = (int)(a); (i) < (int)(b); ++(i))
#define rFor(i, a, b) for (int(i) = (int)(a)-1; (i) >= (int)(b); --(i))
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef unsigned long long ulint;
typedef pair<int, int> pii;
typedef pair<lint, lint> pll;
template <class T>
bool chmax(T &a, const T &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
bool chmin(T &a, const T &b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
T div_floor(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a >= 0 ? a / b : (a + 1) / b - 1;
}
template <class T>
T div_ceil(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a > 0 ? (a - 1) / b + 1 : a / b;
}

constexpr lint mod = 1000000007;
constexpr lint INF = mod * mod;
constexpr int MAX = 200010;

template <typename T, typename E, typename F, typename G>
struct SegTree {
    int sz = 1, seq_sz;
    T et;
    F f;
    G g;
    vector<T> node;

    SegTree(int sz_, T et, F f, G g) : seq_sz(sz_), et(et), f(f), g(g) {
        while (sz < sz_) sz <<= 1;
        node.resize(sz << 1, et);
    }

    void build(vector<T> &a) {
        rep(i, a.size()) node[i + sz] = a[i];
        rFor(i, sz, 1) node[i] = f(node[i << 1], node[(i << 1) + 1]);
    }

    void build(T x) {
        rep(i, seq_sz) node[i + sz] = x;
        rFor(i, sz, 1) node[i] = f(node[i << 1], node[(i << 1) + 1]);
    }

    void update(int i, E x) {
        i += sz;
        node[i] = g(node[i], x);
        i >>= 1;
        while (i) {
            node[i] = f(node[i << 1], node[(i << 1) + 1]);
            i >>= 1;
        }
    }

    T query(int l, int r) {
        T vl = et, vr = et;
        for (l += sz, r += sz; l < r; l >>= 1, r >>= 1) {
            if (l & 1) vl = f(vl, node[l++]);
            if (r & 1) vr = f(node[--r], vr);
        }
        return f(vl, vr);
    }

    int search_left(int l, const T val, function<bool(T, T)> cmp,
                    function<bool(T, T)> check) {
        T sum = et;
        for (l += sz;; l >>= 1) {
            if (check(f(sum, node[l]), val)) {
                while (l < sz) {
                    if (check(f(sum, node[l << 1]), val))
                        l <<= 1;
                    else {
                        sum = f(sum, node[l << 1]);
                        l = (l << 1) + 1;
                    }
                }
                return l - sz;
            }
            if (__builtin_popcount(l + 1) == 1) return seq_sz;
            if (l & 1) sum = f(sum, node[l++]);
        }
    }

    int search_right(int r, const T val, function<bool(T, T)> cmp,
                     function<bool(T, T)> check) {
        T sum = et;
        for (r += sz;; r >>= 1) {
            if (check(f(sum, node[r]), val)) {
                while (r < sz) {
                    if (check(f(node[(r << 1) + 1], sum), val))
                        r = (r << 1) + 1;
                    else {
                        sum = f(node[(r << 1) + 1], sum);
                        r <<= 1;
                    }
                }
                return r - sz;
            }
            if (__builtin_popcount(r) == 1) return -1;
            if (!(r & 1)) sum = f(node[r--], sum);
        }
    }

    int lower_bound_left(int l, const T val,
                         function<bool(T, T)> cmp = less<>()) {
        auto check = [&cmp](auto a, auto b) { return !cmp(a, b); };
        return search_left(l, val, cmp, check);
    }

    int upper_bound_left(int l, const T val,
                         function<bool(T, T)> cmp = less<>()) {
        auto check = [&cmp](auto a, auto b) { return cmp(b, a); };
        return search_left(l, val, cmp, check);
    }

    int lower_bound_right(int l, const T val,
                          function<bool(T, T)> cmp = greater<>()) {
        auto check = [&cmp](auto a, auto b) { return !cmp(b, a); };
        return search_right(l, val, cmp, check);
    }

    int upper_bound_right(int l, const T val,
                          function<bool(T, T)> cmp = greater<>()) {
        auto check = [&cmp](auto a, auto b) { return cmp(a, b); };
        return search_right(l, val, cmp, check);
    }
};
vector<int> v;

int idx(int x) { return lower_bound(v.begin(), v.end(), x) - v.begin(); }

int main() {
    int n;
    scanf("%d", &n);
    int a[n];
    rep(i, n) {
        scanf("%d", &a[i]);
        v.push_back(a[i]);
    }
    sort(v.begin(), v.end());
    v.erase(unique(v.begin(), v.end()), v.end());
    auto f = [](int x, int y) { return max(x, y); };
    SegTree<int, int, decltype(f), decltype(f)> st_f1(n, 0, f, f),
        st_f2(n, 0, f, f), st_b1(n, 0, f, f), st_b2(n, 0, f, f);
    int f1[n], f2[n], b1[n], b2[n];
    rep(i, n) {
        int pos = idx(a[i]);
        f1[i] = st_f1.query(0, pos) + 1;
        f2[i] = st_f2.query(pos + 1, n) + 1;
        st_f1.update(pos, f1[i]);
        st_f2.update(pos, f2[i]);
    }
    rrep(i, n) {
        int pos = idx(a[i]);
        b1[i] = st_f1.query(pos + 1, n) + 1;
        b2[i] = st_b2.query(0, pos) + 1;
        st_b1.update(pos, b1[i]);
        st_b2.update(pos, b2[i]);
    }
    int ans = 0;
    rep(i, n) {
        chmax(ans, (f1[i] + b1[i]) / 2 - 1);
        chmax(ans, (f2[i] + b2[i]) / 2 - 1);
    }
    printf("%d\n", ans);
}