#!/usr/bin/env python3
#fileencoding: utf-8


W, H, C = [int(v) if i < 2 else v for i, v in enumerate(input().strip().split(" "))]
c = ["B","W"]
now = c.index(C)

for i in range(H):
    for j in range(W):
        print(c[now],end="")
        now = (now+1) & 1
    if W % 2 == 0:
        now = (now+1) & 1
    print("")