#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream>
#include <random>
#include<map>
#include <iomanip>
#include <time.h>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
#include <cassert>
#include<fstream>
#include <unordered_map>
#include <cstdlib>
#include <complex>
#include <cctype>
#include <bitset>
using namespace std;
typedef string::const_iterator State;
#define Ma_PI 3.141592653589793
#define eps 1e-5
#define LONG_INF 1e18
#define GOLD 1.61803398874989484820458
#define MAX_MOD 1000000007LL
#define MOD 998244353LL
#define seg_size 262144*4
#define REP(a,b) for(long long a = 0;a < b;++a)
int grid[1000][1000] = {};
int main() {
	int n, k;
	cin >> n >> k;
	for (int lane = 1;; ++lane) {
		int cnt = 0;
		REP(i, lane) {
			REP(q, lane) {
				int hoge = i / k;
				if (q >= hoge * k && q < (hoge + 1) * k) {
					grid[i][q] = 1;
					cnt++;
				}
				else {
					grid[i][q] = 0;
				}
			}
		}
		if (n <= cnt) {
			cout << lane << endl;
			REP(i, lane) {
				REP(q, lane) {
					if (grid[i][q] == 1) {
						cout << "#";
					}
					else {
						cout << ".";
					}
				}
				cout << endl;
			}
			return 0;
		}
	}
}