using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, k) = (c[0], c[1]);
        var m = (n + k - 1) / k;
        var ans = new char[m][];
        var rest = n;
        for (var i = 0; i < m; ++i)
        {
            ans[i] = Enumerable.Repeat('.', m).ToArray();
            for (var j = 0; j < Math.Min(m, k); ++j)
            {
                if (rest > 0)
                {
                    ans[i][(i + j) % m] = '#';
                    --rest;
                }
            }
        }
        WriteLine(m);
        WriteLine(string.Join("\n", ans.Select(ai => string.Concat(ai))));
    }
}