W,H,C = map(str,input().split())
p = ["B","W"]

if C=="B":
    for i in range(int(H)):
        temp=""
        for j in range(int(W)):
            if i%2==0:
                temp+=p[j%2]
            else:
                temp+=p[(j+1)%2]
        print(temp)

else:
    for i in range(int(H)):
        temp=""
        for j in range(int(W)):
            if i%2==0:
                temp+=p[(j+1)%2]
            else:
                temp+=p[j%2]
        print(temp)