#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";}



signed main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(10);
	
	const int MAX = 1100;
	int N, K, con = 0, M = 0;
	vector<vector<int>> ans(MAX, vector<int>(MAX, false));
	vector<int> conh(MAX), conw(MAX);
	
	cin>>N>>K;
	
	
	assert(N >= 1 && N <= 1000 && K >= 1 && K <= N);
	for(int i = 0; ;i++){
		for(int j = i; j >= 0; j--){
			int y = j;
			int x = i;
			if(conh[y] < K && conw[x] < K && con < N && !ans[y][x]){
				conh[y]++;
				conw[x]++;
				ans[y][x] = true;
				con++;
			}
			swap(y,x);
			if(conh[y] < K && conw[x] < K && con < N && !ans[y][x]){
				conh[y]++;
				conw[x]++;
				ans[y][x] = true;
				con++;
			}
		}
		M = i;
		if(con >= N) break;
	}
	
	cout<<M+1<<endl;
	
	for(int i = 0; i <= M; i++){
		for(int j = 0; j <= M; j++){
			cout<<(ans[i][j]?"#":".");
		}
		cout<<endl;
	}
	
	return 0;
}
/*
##..
##..
..##
..##

###...
###...
###...

*/