#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<cassert>

using namespace std;

#define int long long
#define endl "\n"

const long long INF = (long long)1e18;
const long long MOD = 1'000'000'007; 

string yn(bool f){return f?"Yes":"No";}
string YN(bool f){return f?"YES":"NO";}


int N, K;

bool check(int num){
	
	// cout<<num <<" "<<min(K,num)*num <<endl;
	
	if(min(K,num)*num < N) return false;
	
	return true;
}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(10);
	
	const int MAX = 1100;
	int con = 0, M = 0;
	vector<vector<int>> ans(MAX, vector<int>(MAX, false));
	vector<int> conh(MAX), conw(MAX);
	
	cin>>N>>K;
	
	for(int i = 1; ; i++){
		if(check(i)){
			M = i;
			break;
		}
	}
	for(int i = 0; i < M; i++){
		
		for(int j = 0; j < K && j < M; j++){
			if(con++ < N){
				ans[i][(i+j)%M] = true;
			}
		}
	}
	
	cout<<M<<endl;
	
	for(int i = 0; i < M; i++){
		for(int j = 0; j < M; j++){
			cout<<(ans[i][j]?"#":".");
		}
		cout<<endl;
	}
	
	return 0;
}
/*
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*/