#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) __typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii; typedef long long ll;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

struct Val2 {
	typedef pii Val;

	int a1, a2;
	Val x1, x2;

	Val2(): a1(-1), x1(-INF, -1), a2(-1), x2(-INF, -1) { }
	Val2(int a, Val x): a1(a), x1(x), a2(-1), x2(-INF, -1) { }

	void add(int a, Val x) {
		if(a == a1) {
			if(x1 < x)
				x1 = x;
		}else if(x1 < x) {
			a2 = a1, x2 = x1;
			a1 = a, x1 = x;
		}else if(x2 < x) {
			a2 = a, x2 = x;
		}
	}

	Val get(int a) const {
		return a1 != a ? x1 : x2;
	}

	Val2 operator+=(const Val2 &that) {
		add(that.a1, that.x1);
		add(that.a2, that.x2);
		return *this;
	}

	Val2 operator+(const Val2 &that) const {
		return Val2(*this) += that;
	}
};

struct DynamicRMQ {
	typedef Val2 Val;
	int n;
	vector<Val> d;
	void init(int nmin) {
		for(n = 1; n < nmin; n *= 2);
		d.assign(n * 2, Val());
	}
	void add(int i, Val x) {
		d[n+i] += x;
		for(int k = (n+i)/2; k > 0; k >>= 1) 
			d[k] = d[k * 2] + d[k * 2 + 1];
	}
	Val get(int i) const { return d[n+i]; }
	//[l, r)
	Val query(int l, int r) const {
		Val m = Val();
		for(; l && l + (l&-l) <= r; l += l&-l)
			m += d[(n+l) / (l&-l)];
		for(; l < r; r -= r&-r)
			m += d[(n+r) / (r&-r) - 1];
		return m;
	}
};

int main() {
	int N;
	while(cin >> N) {
		vi A(N);
		rep(i, N)
			scanf("%d", &A[i]);
		vi values = A;
		sort(all(values));
		values.erase(unique(all(values)), values.end());
		int X = values.size();
		rep(i, N)
			A[i] = lower_bound(all(values), A[i]) - values.begin();
		DynamicRMQ rmq[2];
		rep(k, 2)
			rmq[k].init(X);
		int ans = 1;
		rep(i, N) {
			int a = A[i];
			Val2 vs[2];
			rep(k, 2) {
				pii x;
				if(k == 0) {
					x = rmq[k ^ 1].query(a + 1, X).get(a);
				} else {
					x = rmq[k ^ 1].query(0, a).get(a);;
				}
				if(x.first == -INF)
					continue;
				amax(ans, x.first + 1);
				int m = x.second;
				Val2 v(x.second, mp(x.first + 1, a));
				if(k == 0) {
					assert(a < m && m < X);
					pii y = rmq[k ^ 1].query(m + 1, X).get(a);
					v += Val2(y.second, mp(y.first + 1, a));
					pii z = rmq[k ^ 1].query(a + 1, m).get(a);
					v += Val2(z.second, mp(z.first + 1, a));
				} else {
					assert(0 <= m && m < a);
					pii y = rmq[k ^ 1].query(m + 1, a).get(a);
					v += Val2(y.second, mp(y.first + 1, a));
					pii z = rmq[k ^ 1].query(0, m).get(a);
					v += Val2(z.second, mp(z.first + 1, a));
				}
				vs[k] = v;
			}
			rep(k, 2)
				rmq[k].add(a, vs[k]);
			rep(k, 2)
				rmq[k].add(a, Val2(-2, mp(1, a)));
		}
		if(ans <= 2)
			ans = 0;
		printf("%d\n", ans);
	}
	return 0;
}