#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<tuple>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define Per(i,sta,n) for(int i=n-1;i>=sta;i--)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;

int n,k;

void solve(){
	cin >> n >> k;
	char S[1010][1010];
	int m=0;
	while(m*k<n){
		m++;
	}
	rep(i,m){
		rep(j,m){
			S[i][j]='.';
		}
	}
	int cnt=0;
	bool flag=false;
	rep(i,m){
		rep(j,k){
			//cout << cnt << endl;
			//cout << i << " " << (i+j)%m << endl;
			S[i][(i+j)%m]='#';
			cnt+=1;
			if(cnt==n) {
				flag=true;
				break;
			}
		}
		if (flag) break;
	}
	cout << m << endl;
	rep(i,m){
		rep(j,m){
			cout << S[i][j];
		}
		cout << "" << endl;
	}
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(50);
	solve();
}