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

all_c = "WB"
reverse_c = all_c.replace(c, "")

for i in range(int(h)):
    for j in range(int(w)):
        if (i + j) % 2 == 0:
            print(c, end="")
        else:
            print(reverse_c, end="")
    print()