T = gets.to_i

T.times do
  n = gets.to_i
  a = gets.split.map(&:to_i)
  dp = Array.new(n + 3) { Array.new(3, 0) }
  ans = 0

  n.times do |i|
    j = (i + 1) % n
    k = (i + 2) % n

    3.times do |d|
      if dp[i + 1][d] < dp[i][d]
        dp[i + 1][d] = dp[i][d]
      end
    end

    next if a[i] == a[j] || a[i] == a[k] || a[j] == a[k]
    next if a[i] < a[j] && a[j] < a[k]
    next if a[i] > a[j] && a[j] > a[k]

    if 0 <= i && i + 2 < n
      dp[i + 3][0] = dp[i][0] + a[i]
      ans = dp[i + 3][0] if ans < dp[i + 3][0]
    end

    if 1 <= i && i + 1 < n
      dp[i + 3][1] = dp[i][1] + a[i]
      ans = dp[i + 3][1] if ans < dp[i + 3][1]
    end

    if 2 <= i
      dp[i + 3][2] = dp[i][2] + a[i]
      ans = dp[i + 3][2] if ans < dp[i + 3][2]
    end
  end

  puts ans
end