#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<bitset>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<functional>
#include<cstdio>
#include<cstdlib>
using namespace std;

#define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(i, n) repr(i, 0, n)
#define INF 2e9
#define MOD 1000000007
//#define MOD 998244353
#define LINF (long long)4e18
#define jck 3.141592

const double EPS = 1e-10;

using ll = long long;
using Pi = pair<int,int>;
using Pl = pair<ll,ll>;


int main(){
    int N; cin >> N;
    vector<int> A(N);
    rep(i,N) cin >> A[i];
    int ans = 0;
    bool ok = false;
    for(int i = 0; i < N; i+=2){
        ans++;
        if(i < N-2 && A[i] == A[i+1] && A[i+1] == A[i+2]) ans++;
        if(i > 0 && i < N-1 && A[i-1] == A[i] && A[i] == A[i+1]) ok = true;
    }
    if(ans == (N+1)/2 && ok) ans++;
    cout << ans << endl;
}