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

head = "B" if c == "W" else "W"

for i in range(int(h)):
    if head == "W":
        pre = "W"
    else:
        pre = "B"

    for j in range(int(w)):

        if pre == "B":
            print("W", end="")
            pre = "W"

            if j == 0:
                head = "W"
        else:
            print("B", end="")
            pre = "B"

            if j == 0:
                head = "B"
    print()