w, h, c = gets.strip.split(' ')
w = w.to_i
h = h.to_i
result = ''
w.times {|i|
  h.times {|j|
    result +=
    if i % 2 == 0
      then
        if j % 2 == 0 then '0' else '1' end
      else
        if j % 2 == 1 then '0' else '1' end
    end
  }
  result += "\n"
}

if c === 'W' then
  result.gsub!('0', 'W').gsub!('1', 'B')
else
  result.gsub!('0', 'B').gsub!('1', 'W')
end

puts result