#include<iostream>
#include<string>
#include<cstdio>
#include<cstring>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<deque>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
using namespace std;

typedef long long ll;
typedef unsigned long long ul;
typedef unsigned int ui;
typedef long double ld;
const int inf=1e9+7;
const ll longinf=1LL<<60 ;
const ll mod=1e9+7 ;
#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 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 complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<int, int> P;
typedef pair<ld, ld> LDP;
typedef pair<ll, ll> LP;
typedef vector<int> vec;
typedef vector<vector<int>> mat;
#define fr first
#define sc second
#define all(c) c.begin(),c.end()
#define pb push_back
#define debug(x)  cout << #x << " = " << (x) << endl;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
//#define int long long

void solve() {
	int n, k; cin >> n >> k;
    int cnt = n / (k * k), amari = n % (k * k), amarihen;
	rep1(i, k) {
		if(i * i >= amari) {
			amarihen = i;
			break;
		}
	}
	if(k * k * cnt == n) {
		amarihen = 0;
	}
	int m = k * cnt + amarihen;
	cout << m << endl;
	char a[1010][1010];
	rep(i, m) {
		rep(j, m) {
			if(i / k == j / k) {
				a[i][j] = '#';
			} else {
				a[i][j] = '.';
			}
		}
	}
	int muda = k * k * cnt + amarihen * amarihen - n;
	int i = 0, j = 0;
	while(muda > 0) {
		a[i][j] = '.';
		muda --;
		if(j < k - 1) {
			j ++;
		} else {
			i ++; j = 0;
		}
	}
	rep(i, m) {
		rep(j, m) {
			cout << a[i][j];
		}
		cout << endl;
	}
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(10);
	//init();
	solve();
	//cout << "finish" << endl;
    return 0;
}