W, H, C = map(str, input().split())
W = int(W)
H = int(H)
s1 = "BW"
s2 = "WB"
if C == "B":
    for i in range(1,H + 1):
        if i % 2 == 0:
            ans = s2 * (W //2)
            if W % 2 != 0:
                ans += "W"
            print(ans)
        else:
            ans = s1 * (W // 2)
            if W % 2 != 0:
                ans += "B"
            print(ans)
else:
    for i in range(1, H + 1):
        if i % 2 == 0:
            ans = s1 * (W //2)
            if W % 2 != 0:
                ans += "B"
            print(ans)
        else:
            ans = s2 * (W // 2)
            if W % 2 != 0:
                ans += "W"
            print(ans)