#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define READ_BUFSIZE ( 1024 )
#define READ_DELIMITER ( " " )

#define ICHI ("BWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWBWB")



int main(int argc, char *argv[]) 
{

	int W = 0;
	scanf("%d", &W);

	int H = 0;
	scanf("%d", &H);

	char C[2] = "";
	scanf("%s", C);

	char* p1 = 0;
	char* p2 = 0;

	if( C[0] == 'B')
	{
		p1 = ICHI;
		p2 = p1 + 1;
	}
	else
	{
		p2 = ICHI;
		p1 = p2 + 1;

	}
	for (int i = 0; i < H; i++)
	{
		if( i == 0 || i % 2 == 0 )
			printf("%.*s\n", W, p1 );
		else
			printf("%.*s\n", W, p2);

	}



	return 0;

}