if __name__ == "__main__":
	N = int(input())
	A = list(map(int, input().split()))

	dp = [[0 for i in range(2)] for i in range(N + 1)]
	for i in range(N):
		dp[i + 1][0] = max(dp[i][1], dp[i][0])

		dp[i + 1][1] = dp[i][0] + 1
		if i == 0 or A[i - 1] == A[i]:
			dp[i + 1][1] = max(dp[i + 1][1], dp[i][1] + 1)

	print(max(dp[N][0], dp[N][1]))