#include<bits/stdc++.h>
using namespace std;

int main(){
	int N;
	cin >> N;
	vector<int> A(N);
	for(int i = 0; i < N; i++) cin >> A[i];
	
	int ans = 0;
	int res = 0;
	
	for(int i = 0; i < N; i += 2){
		while(i < N && A[i] == A[i+1]){
			ans++;
			i++;
		}
		ans++;
	}
	
	for(int i = 1; i < N; i += 2){
		while(i < N && A[i] == A[i+1]){
			res++;
			i++;
		}
		res++;
	}
	
	cout << max(ans, res) << endl;
			
}