N = gets.to_i
A = gets.split.map(&:to_i)

dp = Array.new(N) { Array.new(2, false) }
dp[0][0] = true

1.upto(N - 1) do |i|
  if dp[i - 1][1]
    dp[i][0] = false
  end

  if A[i] > 1 && !dp[i][0]
    dp[i][1] = true
  end
end

if dp.last.last
  puts 'Alice'
else
  puts 'Bob'
end