w, h, c_1 = input().split()
w = int(w)
h = int(h)
c_2 = 0
if c_1 == "B":
    c_2 = "W"
elif c_1 == "W":
    c_2 = "B"

if w > 1:
    im_1 = c_1 + c_2
    for i in range(w//2 - 1):
        im_1 += im_1

    if w % 2 == 1:
        im_1 += c_1

    im_2 = c_2 + c_1
    for i in range(w//2 - 1):
        im_2 += im_2

    if w % 2 == 1:
        im_2 += c_2

elif w == 1:
    im_1 = c_1
    im_2 = c_2

for i in range(h):
    if i % 2 == 0:
        print(im_1)
    if i % 2 == 1:
        print(im_2)