width, height, color1 = gets.split
color2 = color1 == 'W' ? 'B' : 'W'
height.to_i.times do |i|
  array = []
  width.to_i.times do |j|
    if i.even?
    array << (j.even? ? color1 : color2)
    else
    array << (j.even? ? color2 : color1)
    end
  end
  puts array.join
end