using System;
using System.Text;
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 even = s[2];
        string odd;
        if(even == "W")
        {
            odd = "B";
        }
        else
        {
            odd = "W";
        }
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < h; i++)
        {
            for(int j = 0; j < w; j++)
            {
                if((i + j) % 2 == 0)
                {
                    sb.Append(even);
                }
                else
                {
                    sb.Append(odd);
                }
            }
            sb.Append("\r\n");
        }
        Console.WriteLine($"{sb.ToString().Trim()}");
    }
}