W, H, C = map(str,input().split())
color = [""] * 2
S = [""] * 2
if C == "B":
    color[0] = "B"
    color[1] = "W"
else:
    color[0] = "W"
    color[1] = "B"

S[0] = ""
for i in range(int(W)):
    S[0] += color[i % 2]

S[1] = ""
for i in range(int(W)):
    S[1] += color[(i+1) % 2]

for j in range(int(H)):
    print(S[j % 2])