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

namespace YukiCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var va = Console.ReadLine().Split();
            int nW = int.Parse(va[0]);
            int nH = int.Parse(va[1]);
            bool B = va[2] == "B";            
            StringBuilder sb = new StringBuilder().Insert(0, "BW", nW / 2 + 1);
            for (int i = 0; i < nH; i++)
            {
                if (B)  Console.WriteLine(sb.ToString(i + 0 & 1, nW));
                else    Console.WriteLine(sb.ToString(i + 1 & 1, nW));
            }
            Console.ReadLine();
        }
    }
}