import java.io.*;
import java.util.*;
import java.math.*;

class Main82 {
	
	public static void out (Object out) {
		System.out.println(out);
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		String[] line = br.readLine().split(" ");
		int w = Integer.parseInt(line[0]);
		int h = Integer.parseInt(line[1]);
		boolean startB = line[2].equals("B");
		
		for (int i = 0; i < h; i++) {
			boolean flg = startB;
			for (int j = 0; j < w; j++) {
				System.out.print(flg ? "B" : "W");
				flg = !flg;
			}
			out("");
			startB = !startB;
		}
		
	}
}