w, h, c = input().split()
w, h = int(w), int(h)

for _ in range(h):
    for _ in range(w):
        print(c, end = "")
        if c == "B":
            c = "W"
        else:
            c = "B"
    print()
    if w % 2 == 0:
        if c == "B":
            c = "W"
        else:
            c = "B"