#include <bits/stdc++.h>

int ri() {
	int n;
	scanf("%d", &n);
	return n;
}

int main() {
	int n = ri();
	int a[n + 1];
	for (int i = 0; i < n; i++) a[i] = ri();
	int dp[n + 1];
	memset(dp, 0, sizeof(dp));
	for (int i = 0; i < n; i++) {
		dp[i + 1] = std::max(dp[i + 1], dp[i]);
		if (a[i] != a[i + 1]) dp[std::min(i + 2, n)] = std::max(dp[std::min(i + 2, n)], dp[i] + 1);
		else dp[i + 1] = std::max(dp[i + 1], dp[i] + 1);
	}
	std::cout << dp[n] << std::endl;
	return 0;
}