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

namespace template
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] s = Console.ReadLine().Split();
            bool isB = s[2] == "B";
            for (int i = 0; i < int.Parse(s[1]); i++)
            {
                for (int j = 0; j < int.Parse(s[0]); j++)
                {
                    Console.Write(isB ? 'W' : 'B');
                    isB = !isB;
                }
                Console.WriteLine();
            }
        }
    }
}