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// Wiktor Cupiał
// TU Delft
 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
#define mp make_pair
#define pb push_back
#define ppb pop_back
#define pf push_front
#define ppf pop_front
#define eb emplace_back
#define st first
#define nd second
#define vt vector
#define VAR(__var)  #__var << ": " << __var << " "
#define PAIR(__var) #__var << ": " << __var.first << ", " << __var.second << " "
#define FOR(__var, __start, __end)  for(int __var=__start; __var<__end; ++__var)
#define FORB(__var, __start, __end) for(int __var=__start; __var>__end; --__var)
#define maxi(__x, __y) __x = (__x>__y?__x:__y)
#define mini(__x, __y) __x = (__x<__y?__x:__y)
#define all(__var)     (__var).begin(),(__var).end()
#define rall(__var)    (__var).rbegin(),(__var).rend()
#define sz(__var)      (int)(__var).size()
#define satori         int __test; cin>>__test; while(__test--)
 
#ifndef DEBUG
#define DEBUG 0
#endif
#define debug if(DEBUG)
 
using namespace std;
 
using namespace __gnu_pbds;
template <typename T>
using ord_set = tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
 
// templeos <3
typedef     int16_t i16;
typedef     int32_t i32;
typedef     int64_t i64;
typedef        void  u0;
typedef        bool  u1;
typedef        char  u8;
typedef    uint16_t u16;
typedef    uint32_t u32;
typedef    uint64_t u64;
typedef       float f32;
typedef      double f64;
typedef long double f86;
 
typedef       long long ll;
typedef     long double ld;
typedef   pair<ll, ll> pll;
typedef pair<int, int> pii;
 
const int INF = 1e9+2137;

int32_t main() {
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

	int n;
	cin >> n;

	vt<int> a(n);
	for(auto &x : a)
		cin >> x;

	vt<vt<vt<int>>> dp(n, vt<vt<int>>(3, vt<int>(2, INF)));
	FOR(i, 1, 3)
		FOR(j, 0, 2)
			dp[0][i][j] = 1;
	dp[0][0][0] = 0;
	dp[0][0][1] = 0;

	FOR(i, 1, n) {
		if(a[i-1] > a[i])
			mini(dp[i][0][1], dp[i-1][0][0]);
		if(a[i-1] < a[i])
			mini(dp[i][0][0], dp[i-1][0][1]);
		mini(dp[i][0][1], dp[i-1][2][0]);
		mini(dp[i][0][0], dp[i-1][1][1]);

		mini(dp[i][1][1], dp[i-1][0][0]+1);
		mini(dp[i][1][1], dp[i-1][2][0]+1);

		mini(dp[i][2][0], dp[i-1][0][1]+1);
		mini(dp[i][2][0], dp[i-1][1][1]+1);
	}
	
	int res = INF;
	FOR(i, 0, 3)
		FOR(j, 0, 2)
			mini(res, dp[n-1][i][j]);
	cout << res << '\n';

	return 0;
}