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

z = [0]*N
pre=10**6
dp = [[0]*2 for _ in range(N)]

dp[0][1]=1
for i in range(1,N):
    dp[i][0]=max(dp[i-1][0],dp[i-1][1])
    if A[i]==A[i-1]:
        dp[i][1] = max(dp[i-1][0],dp[i-1][1])+1
    else:
        dp[i][1] = max(dp[i-1][0]+1, dp[i-1][1])

print(max(dp[-1]))