W, H, C = map(str, raw_input().split())
W = int(W)
H = int(H)

st = ["B", "W"]

if st[0] != C:
    st.reverse()

for _ in xrange(H):

    row = ""
    for i in xrange(W):
        row += st[i % 2]

    print row
    st.reverse()