using System;
using System.Linq;

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

        string a = "W";
        string b = "B";
        if (s[2] == "B")
        {
            a = "B";
            b = "W";
        }

        for (int i = 0; i < h; i++)
        {
            for (int j = 0; j < w; j++)
            {
                if ((i + j) % 2 == 0) Console.Write(a);
                else Console.Write(b);
            }
            Console.WriteLine();
        }
    }
}