W,H,C=input().split()
W,H=int(W),int(H)
if C=="B":
    D="W"
else:
    D="B"
for i in range(H):
    for j in range(W):
        if ((i+j)%2==0):
            print(C,end="")
        else:
            print(D,end="")
    print("")