#!/usr/bin/env ruby
program_name = $0.split("/").last
lines = ARGV[0].to_i
numargs = ARGV.length

#just for testing
#numargs = 1
#lines = 8


case numargs
        when 0
          puts "Error. No arguments given. Try #{program_name} --help"
        when 1
          puts "Printing #{lines} lines...\n"
          # control variables
a = 3
b = 1
i = 1
j = 1
output = ""

while i <= lines
while j <= i

    if a == 0 && b == 0
      a = 3
      b = 1

        elsif a > 0
          output << "A"
          a = a - 1

    else
      output << "B"
      b = b - 1
    end
    j = j + 1
  end
puts output
i = i + 1
end


        else
          puts "Too many arguments given. Try #{program_name} --help"