//include
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <unordered_map>
#include <climits>
#include <set>
#include <unordered_set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <queue>
#include <random>
#include <complex>
#include <regex>
#include <locale>
#include <random>
#include <type_traits>

using namespace std;

#define SHOW_VECTOR(v) {std::cerr << #v << "\t:";for(const auto& xxx : v){std::cerr << xxx << " ";}std::cerr << "\n";}
#define SHOW_MAP(v){std::cerr << #v << endl; for(const auto& xxx: v){std::cerr << xxx.first << " " << xxx.second << "\n";}}

using LL = long long;

//------------------------------------------
//------------------------------------------


int main() {

    int N, K;
    cin >> N >> K;

    if (N <= K * K) {
        for (int i = 1; i <= 1000; i++) {
            if (i * i >= N) {
                vector<vector<char>> ans(i, vector<char>(i, '.'));
                for (int j = 0; j < i; j++) {
                    for (int k = 0; k < i; k++) {
                        if (N > 0) {
                            ans[j][k % i] = '#';
                            N--;
                        }
                    }
                }
                cout << i << endl;
                for (int j = 0; j < i; j++) {
                    for (int k = 0; k < i; k++) cout << ans[j][k];
                    cout << endl;
                }
                return 0;
            }
        }
    }

    for (int i = 1; i <= 100000; i++) {
        int d = i * K;
        if (d >= N) {

            vector<vector<char>> ans(i, vector<char>(i, '.'));
            // for (int j = 0; j < i; j++) SHOW_VECTOR(ans[j]);

            for (int j = 0; j < i; j++) {
                for (int k = 0; k < K; k++) {
                    if (N > 0) {
                        ans[j][(j + k) % i] = '#';
                        N--;
                    }
                }
            }
            cout << i << endl;
            for (int j = 0; j < i; j++) {
                for (int k = 0; k < i; k++) cout << ans[j][k];
                cout << endl;
            }

            return 0;
        }
    }


    return 0;
}