class Program
{
    static void Main(string[] args)
    {
        string[] inputData = Console.ReadLine()!.Split(' ');
        int width = int.Parse(inputData[0]);
        int height = int.Parse(inputData[1]);

        for (int i = 1; i <= height; i++)
        {
            for (int j = 1; j <= width; j++)
            {
                if (inputData[2] == "B")
                {
                    if (j % 2 == 0)
                    {
                        Console.Write("W");
                    }
                    else
                    {
                        Console.Write("B");
                    }
                }
                else
                {
                    if (j % 2 == 0)
                    {
                        Console.Write("B");
                    }
                    else
                    {
                        Console.Write("W");
                    }
                }
            }
            if (inputData[2] == "B")
            {
                inputData[2] = "W";
            }
            else
            {
                inputData[2] = "B";
            }
            Console.WriteLine();
        }
    }
}