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=0; i < w; i++)
			    for(int j=1; j < h; j+=2)  ichimatsu[j][i] = "W";
		    for(int i=0; i < w; i++)
			    for(int j=2; j < h; j+=2)  ichimatsu[j][i] = "B";
		} else{
			for(int i=0; i < w; i++)
			    for(int j=1; j < h; j+=2)  ichimatsu[j][i] = "B";
			for(int i=0; i < w; i++)
			    for(int j=2; j < h; j+=2)  ichimatsu[j][i] = "W";
		}
		if(ichimatsu[0][0].equals("B")){
		    for(int i=0; i < h; i++)
			    for(int j=1; j < w; j+=2)  ichimatsu[i][j] = "W";
		    for(int i=0; i < h; i++)
			    for(int j=2; j < w; j+=2)  ichimatsu[i][j] = "B";
		} else{
			for(int i=0; i < h; i++)
			    for(int j=1; j < w; j+=2)  ichimatsu[i][j] = "B";
			for(int i=0; i < h; i++)
			    for(int j=2; j < w; j+=2)  ichimatsu[i][j] = "W";
		}
		for(int i=0; i < h; i++){
			for(int j=0; j < w; j++){
				System.out.print(ichimatsu[i][j]);
			}
			System.out.println("");
		}
	}
}