package me.yukicoder.lv1;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;

public class No0082 {
	public static void main(String[] args) {
		try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
			String[] str = br.readLine().split(" ");
			int W = Integer.parseInt(str[0]);
			int H = Integer.parseInt(str[1]);

			char[] ichimatsu = new char[2];
			ichimatsu[0] = str[2].charAt(0);
			if (ichimatsu[0] == 'W')
				ichimatsu[1] = 'B';
			else
				ichimatsu[1] = 'W';

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

		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}