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

public class Main {
	public static void main(String[] args) {
		BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));

		try {
			String[] box = buff.readLine().split(" ");
			int width = Integer.parseInt(box[0]);
			int height = Integer.parseInt(box[1]);
			String[] str = new String[2];

			if(box[2].equals("B")){
				str[0] = "B";
				str[1] = "W";
			}else{
				str[0] = "W";
				str[1] = "B";
			}

			for(int i = 0; i < height; ++i){
				for(int j = 0; j < width; ++j){
					if(i % 2 == 0){
						if(j % 2 == 0){
							System.out.print(str[0]);
						}else{
							System.out.print(str[1]);
						}
					}else{
						if(j % 2 == 0){
							System.out.print(str[1]);
						}else{
							System.out.print(str[0]);
						}
					}
				}
				System.out.println();
			}

		} catch (NumberFormatException e) {
			e.getStackTrace();
		} catch (IOException e) {
			e.getStackTrace();
		} catch (Exception e) {
			e.getStackTrace();
		}
	}
}