import java.util.*; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int W = sc.nextInt(), H = sc.nextInt(); String C = sc.next(); String[][] mark = new String[W][H]; String C2; if(C.equals("B")) { C2 = "W"; } else { C2= "B"; } for(int i = 0; i < H; i++) { for(int j = 0; j < W; j++) { if(i % 2 == 0 && j % 2 != 0) { mark[j][i] = C2; } else if(i % 2 != 0 && j % 2 == 0) { mark[j][i] = C2; } else { mark[j][i] = C; } } } for(int i = 0; i < H; i++) { for(int j = 0; j < W; j++) { System.out.print(mark[j][i]); } System.out.println(); } } }