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#include <chrono>
#include <cassert>
#include <string>
#include <array>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#include <iterator>
#include <algorithm>
#include <cmath>
#include <complex>
#include <numeric>
#include <random>
#include <ios>
#include <iostream>
#include <bitset>
using namespace std; 

#define fwd(i, a, b) for (int i = (a); i < (b); ++ i)
#define rep(i, n) for (int i = 0; i < (n); ++ i)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)x.size())
#define st first
#define nd second
#define pii pair<int, int>
#define vi vector<int>
#define fastio ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define ll long long

#ifdef LOCAL
template<typename Stream, typename T1, typename T2>
Stream& operator << (Stream& out, pair<T1, T2> a) {return out << "(" << a.st << ", " << a.nd << ")";}
 
template<typename Stream, typename T>
Stream &operator << (Stream& out, T v) {
	out << "{";
	int i = 0;
	for (auto x : v)
		out << x << ((++ i) != sz(v) ? ", " : "");
	return out << "}";
}

template<typename... Args>
void dump(Args... x) {((cerr << x << ", "), ...) << '\n';}
 
#define debug(x...) cerr << "[" #x "]: ", dump(x)
#else
#define debug(...) 0
#endif

int32_t main() {
	fastio;
	int n;
	cin >> n;
	const int inf = 1e9 + 2137;
	int a = inf, b = -inf;
	int ac = 0, bc = 0;
	rep(i, n) {
		int x;
		cin >> x;
		if (i & 1) {
			if (x > a) {
				a = x;
			} else {
				++ ac;
				a = inf;
			}
			if (x < b) {
				b = x;
			} else {
				++ bc;
				b = -inf;
			}
		} else {
			if (x < a) {
				a = x;
			} else {
				++ ac;
				a = -inf;
			}
			if (x > b) {
				b = x;
			} else {
				++ bc;
				b = inf;
			}
		}
	}
	cout << min(ac, bc) << '\n';
	return 0;
}