class Calc0082
  def initialize(args)
    args = args.map { |l| l.chomp.split(/\s+/) }
    @w, @h, @c = args.shift
    @w, @h = [@w, @h].map(&:to_i)
  end

  def run
    @h.times.map { |h|
      @w.times.map { |w|
        ((w + h).even? ^ (@c == 'B')) ? 'W' : 'B'
      }.join
    }.join("\n")
  end
end

puts Calc0082.new(STDIN.readlines).run if __FILE__ == $0