#include <iostream>
using namespace std;
typedef signed long long ll;
 
#define REP(i,n) for (int i = 0; i < (n); i++)
#define RREP(i,n) for (int i = (n)-1; i >= 0; i--)
#define FOR(i,s,n) for (int i = (s); i < (n); i++)
#define RFOR(i,s,n) for (int i = (n)-1; i >= (s); i--)
 
 
int main() {

	int c,r;
	char color;
	bool flag;
	
	cin >> c >> r >> color;
	(color == 'B')?flag=true:flag=false;

	for(int i = r; i > 0; i--){	
		for (int j = c;j > 0;j--){
			cout <<  (flag ? "B" : "W");
			flag = !flag;
		}cout << endl;
		if (c%2==0)flag = !flag;
	}

	return 0;
}