#  coding=UTF-8:
import itertools

def moyou(W, H, C):
    moyouListA = "WB"
    moyouListB = "BW"
    moyouLine = ""
    W, H = int(W), int(H)
    Wc, Hc = 0, 0
    if C == "W":
        for i in itertools.cycle(moyouListA):
            moyouLine += i
            if len(moyouLine) == W * H:
                break
    elif C == "B":
        for i in itertools.cycle(moyouListB):
            moyouLine += i
            if len(moyouLine) == W * H:
                break
    ansLine = list([moyouLine[i:i+W] for i in range(len(moyouLine)//W)])
    for string in ansLine:
        print(string, sep="\n")
    return

w, h, c = map(str, input().split())
moyou(w, h, c)