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

namespace ForYukicoder
{
    //No.82 市松模様
    class Program
    {
        static void Main(string[] args)
        {
            string[] str = Console.ReadLine().Split();
            int W = int.Parse(str[0]);
            int H = int.Parse(str[1]);
            char C = char.Parse(str[2]);
            //-----------------------------

            bool isWhiteRow = (C.Equals('W')) ? true : false;
            bool isWhiteColumn;
            string str2;

            for (int i = 0; i < H; i++)
            {
                isWhiteColumn = isWhiteRow;

                str2 = "";
                for (int j = 0; j < W; j++)
                {
                    str2 += isWhiteColumn ? "W" : "B";
                    isWhiteColumn = isWhiteColumn ? false : true;
                }

                isWhiteRow = isWhiteRow ? false : true;

                Console.WriteLine(str2);
            }
        }
    }
}