#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
constexpr int mod=1000000007;
constexpr int mod1=998244353;
vector<int> dx={0,1,0,-1},dy={-1,0,1,0};
bool inside(int y,int x,int h,int w){
	if(y<h && y>=0 && x<w && x>=0) return true;
	return false;
}





int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	int n;cin >> n;
	vector<int> a(n);
	rep(i,n) cin >> a.at(i);
	int ans = 0;
	if(n % 2 == 0){
		ans = n / 2;
		int cnt1 = 0, cnt2 = 0;
		for(int i = 2; i < n; i += 2){
			if(a.at(i - 1) == a.at(i) && a.at(i) == a.at(i + 1)) cnt1++;
		}
		if(a.at(0) == a.at(1)) cnt1++;
		for(int i = 1; i < n - 1; i += 2){
			if(a.at(i - 1) == a.at(i) && a.at(i) == a.at(i + 1)) cnt2++;
		}
		if(a.at(n - 1) == a.at(n - 2)) cnt2++;
		ans += max(cnt1, cnt2);
	}
	else{
		ans = n / 2 + 1;
		int cnt1 = 0, cnt2 = 0;
		for(int i = 2; i < n - 1; i += 2){
			if(a.at(i - 1) == a.at(i) && a.at(i) == a.at(i + 1)) cnt1++;
		}
		if(a.at(0) == a.at(1)) cnt1++;
		if(a.at(n - 1) == a.at(n - 2)) cnt1++;
		for(int i = 1; i < n; i += 2){
			if(a.at(i - 1) == a.at(i) && a.at(i) == a.at(i + 1)) cnt2++;
		}
		ans += max(cnt1 - 1, cnt2);
	}
	cout << ans << endl;
}