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

s = [[0 for _ in range(w)] for _ in range(h)]

s[0][0] = c
for y in range(h):
    for x in range(w):
        if s[0][0]== "W":
            if (y + x) % 2 == 0:
                s[y][x] = "W"
            else:
                s[y][x] = "B"
        else:
            if (y + x) % 2 == 0:
                s[y][x] = "B"
            else:
                s[y][x] = "W"

for i in range(h):
    print("".join(s[i]))