import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No82 {
	public static void main(String[] args) throws IOException{
		String[] str = new BufferedReader(new InputStreamReader(System.in)).readLine().split(" ");
		int w = Integer.parseInt(str[0]);
		int h = Integer.parseInt(str[1]);
		String[][] ichimatsu = new String[h][w];
		ichimatsu[0][0] = str[2];
		if(ichimatsu[0][0].equals("B")){
			for(int i=1; i < h; i+=2) ichimatsu[i][0] = "W";
			for(int i=2; i < h; i+=2) ichimatsu[i][0] = "B";
		}
		else{
			for(int i=1; i < h; i+=2) ichimatsu[i][0] = "B";
			for(int i=2; i < h; i+=2) ichimatsu[i][0] = "W";
		}
		makeIchimatsu(h,w,ichimatsu);
		for(int i=0; i < h; i++){
			for(int j=0; j < w; j++) System.out.print(ichimatsu[i][j]);
			System.out.println("");
		}
	}
	
	public static void makeIchimatsu(int h, int w, String[][] s){
		for(int i=0; i < h; i++){
			if(s[i][0].equals("B")){
			    for(int j=1; j < w; j+=2)  s[i][j] = "W";
			    for(int j=2; j < w; j+=2)  s[i][j] = "B";
			}
			else{
				for(int j=1; j < w; j+=2)  s[i][j] = "B";
				for(int j=2; j < w; j+=2)  s[i][j] = "W";
			}
		}
	}
}