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

class Program {
    static void Main() {
        string[] s = Console.ReadLine().Split();
        int w = int.Parse(s[0]);
        int h = int.Parse(s[1]);
        char a, b;
        if (s[2] == "B") {
            a = 'B';
            b = 'W';
        } else {
            a = 'W';
            b = 'B';
        }
        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(a);
                } else {
                    sb.Append(b);
                }
            }
            sb.Append('\n');
        }
        Console.Write(sb.ToString());
    }
}