#include <stdio.h>

void main(void){
	int w = 0 , h = 0;
	char selectChar = 'a';
	scanf("%d %d %c",&w,&h,&selectChar);
	int i = 1;
	while(i <= w*h){
		printf("%c",selectChar);
		
		if(w/2 == 0 && i%w != 0 || w/2 != 0){
			if(selectChar == 'B'){
				selectChar = 'W';
			}else if(selectChar == 'W'){
				selectChar = 'B';
			}
		}
		if(i%w == 0){
			printf("\n");
		}
		i++;
	}
}