w,h,c = gets.split(" ")
w = w.to_i
case c
when "B"
	c_rev = "W"
when "W"
	c_rev = "B"
end
pattern = [(c + c_rev) * (w / 2) + c * (w % 2) , (c_rev + c) * (w / 2) + c_rev * (w % 2)]
h.to_i.times{|i|
	puts pattern[i % 2]
}