#include <bits/stdc++.h> 

using i64 = long long; 
using u64 = unsigned long long; 
using u32 = unsigned; 

using u128 = unsigned __int128; 
using i128 = __int128; 

void solve() {
	int W, H;
	char C;
	std::cin >> W >> H >> C;

	char cur = (C == 'B') ? 'W' : 'B';
	for(int i = 0; i < H; i ++) {
		char a = (cur == 'B') ? 'W' : 'B';
		for(int j = 0; j < W; j ++) {
			cur = (cur == 'B') ? 'W' : 'B';
			std::cout << cur;
		}
		cur = a;
		std::cout << " ";
	}
} 

int main() { 
	std::ios::sync_with_stdio(false); 
	std::cin.tie(nullptr); 

	int T = 1; 
	//std::cin >> T; 

	while (T--) { 
		solve(); 
	} 
	return 0; 
}