/*
このコード、と～おれ!
Be accepted!
∧＿∧　
（｡･ω･｡)つ━☆・*。
⊂　　 ノ 　　　・゜+.
　しーＪ　　　°。+ *´¨)
 　　　　　　　　　.· ´¸.·*´¨) ¸.·*¨)
		  　　　　　　　　　　(¸.·´ (¸.·'* ☆
					*/

#include <stdio.h>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstring>
#include <vector>
#include <numeric>
#include <iostream>
#include <random>
#include <map>
#include <unordered_map>
#include <queue>
#include <regex>
#include <functional>
#include <complex>
#include <list>
#include <cassert>
#include <iomanip>
#include <set>
/*多倍長整数/cpp_intで宣言
#include <boost/multiprecision/cpp_int.hpp>
using namespace boost::multiprecision;
*/

//#pragma gcc target ("avx2")
//#pragma gcc optimization ("o3")
//#pragma gcc optimization ("unroll-loops")
#define rep(i, n) for(int i = 0; i < (n); ++i)
#define rep1(i, n) for(int i = 1; i <= (n); ++i)
#define rep2(i, n) for(int i = 2; i < (n); ++i)
#define repr(i, n) for(int i = n; i >= 0; --i)
#define reprm(i, n) for(int i = n - 1; i >= 0; --i)
#define printynl(a) printf(a ? "yes\n" : "no\n")
#define printyn(a) printf(a ? "Yes\n" : "No\n")
#define printYN(a) printf(a ? "YES\n" : "NO\n")
#define printim(a) printf(a ? "possible\n" : "imposible\n")
#define printdb(a) printf("%.50lf\n", a)//少数出力
#define printdbd(a) printf("%.16lf\n", a)//少数出力(桁少なめ)
#define prints(s) printf("%s\n", s.c_str())//string出力
#define all(x) (x).begin(), (x).end()
#define allsum(a, b, c) ((a + b) * c / 2)//等差数列の和、初項,末項,項数
#define pb push_back
#define priq priority_queue
#define rpriq priq<int, vector<int>, greater<int>>
#define deg_to_rad(deg) (((deg)/360.0)*2.0*PI)
#define rad_to_deg(rad) (((rad)/2.0/PI)*360.0)
#define Please return
#define AC 0
#define addf(T) [](T a, T b){return (a + b);}
#define minf(T) [](T a, T b){return min(a, b);}
#define maxf(T) [](T a, T b){return max(a, b);}


using ll = long long;

constexpr int INF = 1073741823;
constexpr int MINF = -1073741823;
constexpr ll LINF = ll(4661686018427387903);
constexpr ll MOD = 1000000007;
const long double PI = acos(-1.0L);

using namespace std;

void scans(string& str) {
	char c;
	str = "";
	scanf("%c", &c);
	if (c == '\n')scanf("%c", &c);
	while (c != '\n' && c != -1) {
		str += c;
		scanf("%c", &c);
	}
}

void scanc(char& str) {
	char c;
	scanf("%c", &c);
	if (c == -1)return;
	while (c == '\n') {
		scanf("%c", &c);
	}
	str = c;
}

double acot(double x) {
	return PI / 2 - atan(x);
}

ll gcd(ll a, ll b) {
	if (b == 0) return a;
	return gcd(b, a % b);
}

ll lcm(ll number1, ll number2) {
	return number1 / gcd(number1, number2) * number2;
}

ll LSB(ll n) { return (n & (-n)); }

/*-----------------------------------------ここからコード-----------------------------------------*/



int main() {

	ll n;
	scanf("%lld", &n);
	vector<ll> a(n + 100), b, c;
	a[0] = a[n + 2] = 0;
	rep(i, n)scanf("%lld", &a[i + 1]);
	rep(i, n) {
		if ((a[i] <= a[i + 1] && a[i + 1] >= a[i + 2]) || (a[i] >= a[i + 1] && a[i + 1] <= a[i + 2]))c.pb(a[i + 1]);
	}
	if (c.empty()) {
		printf("%d\n", !!a[1]);
		Please AC;
	}
	if (c.back() != 0)c.pb(0);
	if(c[0] != 0)c.insert(c.begin(), 0);
	ll siz = c.size();
	b = c;
	sort(all(b));
	b.erase(unique(all(b)), b.end());
	rep(i, siz) {
		c[i] = distance(b.begin(), lower_bound(all(b), c[i]));
	}
	//ここまで座圧
	vector<ll> s(b.size());
	rep(i, siz - 1) {
		ll p = min(c[i], c[i + 1]), q = max(c[i], c[i + 1]);
		if (p == q)continue;
		while (p < q) {
			++s[p];
			++p;
		}
	}

	printf("%lld\n", (ll)*max_element(all(s)) >> 1LL);

	Please AC;
}



Measured memory_bytes: 5484