#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < n; i++)
#define rep1(i,n) for(int i = 1; i <= n; i++)
#define co(x) cout << x <<endl
#define cs(x) cout << x <<" "
#define ALL(a) (a).begin(),(a).end()
typedef long long ll;
using namespace std;
ll mod = 1e9 + 7;

int main()
{
	int n; cin >> n;
	vector<int> a(n);
	vector<int> seq;
	rep(i, n)cin >> a[i];
	int i = 0;
	int ans = 0;
	while (i < n)
	{
		int buf = 1;
		while (true)
		{
			if (a[i] == a[i + 1])
			{
				buf++;
				i++;
			}
			else break;
		}
		seq.push_back(buf);
		i++;
	}
	i = 0;
	while (i<seq.size())
	{
		if (i==seq.size()-1)
		{
			ans += seq[i];
			i++;
		}
		else if (seq[i] >= seq[i + 1])
		{
			ans += seq[i];
			i += 2;
		}
		else if (seq[i] < seq[i + 1])
		{
			ans += seq[i+1];
			i += 3;
		}
	}
	co(ans);
	return 0;
}