W, H, C1 = gets.chomp.split
intw = W.to_i
inth = H.to_i

C2 = C1 == "B" ? "W" : "B"

(1..inth).each do |n|
  (1..intw).each do |i|
    puts create_chars(n, i)
  end
end

def create_chars(n, i)
  output = []

  if (n.odd? && i.odd?) || (n.even? && i.even?)
    output.push(C1)
  else
    output.push(C2)
  end

  output.join
end