n = int(input())
A = list(map(int,input().split()))

#i番目を採用しない→dp[i][0],する→dp[i][1]
#それぞれの最大値
dp = [[0]*2 for _ in range(n)]
dp[0][1] = 1
for i in range(1,n):
    if A[i-1] == A[i]:
        dp[i][1] = max(dp[i-1][1]+1, dp[i-1][0])
        dp[i][0] = max(dp[i-1][0], dp[i-1][1])
    else:
        dp[i][1] = max(dp[i-1][0]+1, dp[i-1][0])
        dp[i][0] = max(dp[i-1][0], dp[i-1][1])
        
print(max(dp[n-1][0], dp[n-1][1]))