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

class TEST{
	static void Main(){
		Sol mySol =new Sol();
		mySol.Solve();
	}
}

class Sol{
	public void Solve(){
		
		int M1 = N / (K * K);
		int rest = N - (K * K) * M1;
		
		int M2 = Math.Min(M1, (rest + K - 1) / K);
		int rest2 = Math.Max(0, rest - M2 * K);
		int M3 = 0;
		while(true){
			if(M3 * M3 >= rest2) break;
			M3++;
		}
		
		int M = M2 * (K + 1) + (M1 - M2) * K + M3;
		char[][] ar = new char[M][];
		for(int i=0;i<M;i++){
			ar[i] = new char[M];
			for(int j=0;j<M;j++) ar[i][j] = '.';
		}
		
		for(int k=0;k<M2;k++){
			for(int i=0;i<K+1;i++){
				for(int j=0;j<K+1;j++){
					ar[K * k + i][K * k + j] = i == j ? '.' : '#';
				}
			}
		}
		for(int k=M2;k<M1;k++){
			for(int i=0;i<K;i++){
				for(int j=0;j<K;j++){
					ar[(K + 1) * M2 + K * (k - M2) + i][(K + 1) * M2 + K * (k - M2) + j] = '#';
				}
			}
		}
		
		for(int i=0;i<M3;i++){
			for(int j=0;j<M3;j++){
				if(rest2 == 0) break;
				ar[(K + 1) * M2 + K * (M1 - M2) + i][(K + 1) * M2 + K * (M1 - M2) + j] = '#';
				rest2--;
			}
		}
		
		Console.WriteLine(M);
		for(int i=0;i<M;i++) Console.WriteLine(new String(ar[i]));
	}
	int N, K;
	public Sol(){
		var d = ria();
		N = d[0]; K = d[1];
	}

	static String rs(){return Console.ReadLine();}
	static int ri(){return int.Parse(Console.ReadLine());}
	static long rl(){return long.Parse(Console.ReadLine());}
	static double rd(){return double.Parse(Console.ReadLine());}
	static String[] rsa(char sep=' '){return Console.ReadLine().Split(sep);}
	static int[] ria(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>int.Parse(e));}
	static long[] rla(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>long.Parse(e));}
	static double[] rda(char sep=' '){return Array.ConvertAll(Console.ReadLine().Split(sep),e=>double.Parse(e));}
}