#include <bits/stdc++.h>
using namespace std::literals::string_literals;
using i64 = long long;
using std::cout;
using std::endl;
using std::cin;

template<typename T>
std::vector<T> make_v(size_t a){return std::vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

int main() {
	int n; scanf("%d", &n); std::vector<int> a(n);
	for(int i = 0; i < n; i++) scanf("%d", &a[i]);

	auto dp = make_v<int>(n + 1, 2);
	for(int i = 0; i < n; i++) {
		dp[i + 1][0] = std::max(dp[i][0], dp[i][1]);

		dp[i + 1][1] = dp[i][0] + 1;
		if(!i or a[i - 1] == a[i]) dp[i + 1][1] = std::max(dp[i + 1][1], dp[i][1] + 1);
	}
	printf("%d\n", std::max(dp[n][0], dp[n][1]));
	return 0;
}