import java.util.Scanner;
public class Main{
	private static char change(char c){
		if(c=='B')return 'W';
		else return 'B';
	}
	public static void main(String args[])throws Exception{
		Scanner sc=new Scanner(System.in);
		String s[]=sc.nextLine().split(" ");
		int w=Integer.parseInt(s[0]);
		int h=Integer.parseInt(s[1]);
		char c=s[2].charAt(0);
		String s1="",s2="";
		for(int i=0;i<w;i++){
			s1+=c;
			c=change(c);
			s2+=c;
		}
		for(int i=0;i<h;i++){
			if(i%2==0)
				System.out.println(s1);
			else
				System.out.println(s2);
		}
	}
}