strinter = input() strs = strinter.split(" ") w_len= int(strs[0]) h_len= int(strs[1]) coler_s =strs[2] data= "" counter=1 for hei_t in range(h_len): for wei_t in range(h_len): if counter%2 ==1: data=data + coler_s else: if coler_s == "W": data=data + "B" else: data=data + "W" counter=counter+1 print(data) data=""