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

C2 = C1 == "B" ? "W" : "B"
str1 = ""

(1..intw).each do |i|
  str1 = if i.odd?
           str1 + C1
         else
           str1 + C2
         end
end

str2 = ""

if inth != 1
  (1..intw).each do |i|
    str2 = if i.odd?
             str2 + C2
           else
             str2 + C1
           end
  end
  (1..inth).each do |i|
    if i.odd?
      puts str1
    else
      puts str2
    end
  end
else
  puts str1
end