using System;

public class Program
{
    public static void Main(string[] args)
    {
        var s = Console.ReadLine().Split(' ');
        int w = int.Parse(s[0]);
        int h = int.Parse(s[1]);
        string c = s[2];

        var pattern = string.Empty;
        if (c == "B")
        {
            for (var i = 0; i < h; i++)
            {
                pattern = string.Empty;
                for (var j = 0; j < w; j++)
                {
                    if (i % 2 == 0) pattern += (j % 2 == 0) ? "B" : "W";
                    else pattern += (j % 2 == 0) ? "W" : "B";
                }
                Console.WriteLine(pattern);
            }
        }
        else
        {
            for (var i = 0; i < h; i++)
            {
                pattern = string.Empty;
                for (var j = 0; j < w; j++)
                {
                    if (i % 2 == 0) pattern += (j % 2 == 0) ? "W" : "B";
                    else pattern += (j % 2 == 0) ? "B" : "W";
                }
                Console.WriteLine(pattern);
            }
        }
    }
}