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

class Program
{
    static void Main(string[] args)
    {
        string[] s = Console.ReadLine().Split();
        int w = int.Parse(s[0]);
        int h = int.Parse(s[1]);
        string[] str;
        string ans;

        if (s[2] == "W")
        {
            str = new string[] { "W", "B" };
        }
        else
        {
            str = new string[] { "B", "W" };
        }

        for (int i = 0; i < h; i++)
        {
            ans = "";
            for (int j = 0; j < w; j++)
            {
                ans += str[(i + j) % 2];
            }

            Console.WriteLine(ans);
        }

        Console.ReadLine();
    }
}