w, h, c = input().split()
w=int(w)
h = int(h)
s1 = "WB"*w
s2 = "BW"*w
if c == "W":
    for i in range(h):
        if (i+1)%2 == 1:
            print(s1[:w])
        else:
            print(s2[:w])
else:
    for i in range(h):
        if (i+1)%2 == 1:
            print(s2[:w])
        else:
            print(s1[:w])