# coding: utf-8
import math

w,h,c = input().split(" ")
w,h = int(w),int(h)
rev = {
    "B":"W",
    "W":"B"
}

for i in range(h):
    for j in range(w):
        if i % 2 == 0:
            if j % 2 == 0:
                print(c,end="")
            else:
                print(rev[c],end="")
        else:
            if j % 2 == 1:
                print(c,end="")
            else:
                print(rev[c],end="")
    print()