N = gets.to_i
dp = Array.new(101, false)

2.upto(N) do |n|
  if n % 2 == 0
    dp[n] = true
  else
    dp[n] |= !dp[n / 3]
    dp[n] |= !dp[n / 2]
  end
end

puts dp[N] ? 'A' : 'B'