using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace yukicoder_82 {
    class Program {
        static void Main(string[] args) {
            //B=66,W=87
            string[] s = Console.ReadLine().Split(' ');
            int w = int.Parse(s[0]);
            int h = int.Parse(s[1]);
            char c = char.Parse(s[2]);
            String[,]color = new string[h, w];
            if (c == 66) {
                for (int i = 0; i < h; i++) {
                    for (int k = 0; k < w; k++) {
                        if (i % 2 == 0) {
                            if (k % 2 == 0) color[i, k] = "B";
                            else color[i, k] = "W";
                        } else {
                            if (k % 2 == 0) color[i, k] = "W";
                            else color[i, k] = "B";
                        }
                    }
                }
            } else {
                for (int i = 0; i < h; i++) {
                    for (int k = 0; k < w; k++) {
                        if (i % 2 == 0) {
                            if (k % 2 == 0) color[i, k] = "W";
                            else color[i, k] = "B";
                        } else {
                            if (k % 2 == 0) color[i, k] = "B";
                            else color[i, k] = "W";
                        }
                    }
                }

            }
            for(int i = 0; i < h; i++) {
                for(int k = 0; k < w; k++) {
                    Console.Write(color[i, k]);
                }
                Console.WriteLine();
            }
            Console.ReadLine();
        }
    }
}