# -*- coding: utf-8 -*-

def switch(c):
    if c == "B":
        return "W"
    else:
        return "B"

def line(c, l):
    result = ""
    for i in range(l):
        result += str(i % 2)
    result = result.replace('0',c)
    result = result.replace('1',switch(c))
    return result

w, h, c = [v if i == 2 else int(v) for i, v in enumerate(input().split())]

for _ in range(h):
    print(line(c, w))
    c = switch(c)