import sys
input=sys.stdin.readline

def main(args):
    N = int(input())
    A = list(map(int,input().split()))
    

    dp = [[0]*2 for _ in range(N)]
    dp[0][1] = 1
    for i in range(1,N):
        dp[i][0] = max(dp[i-1][1], dp[i-1][0])
        dp[i][1] = dp[i-1][0] + 1
        if A[i] == A[i-1]:
            dp[i][1] = max(dp[i][1], dp[i-1][1] + 1)
                                                    
    print(max(dp[-1]))

if __name__ == '__main__':
    main(sys.argv[1:])