#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
using namespace std;

int main()
{
    int n, k;
    cin >> n >> k;

    int m = 1;
    while(m * min(m, k) < n)
        ++ m;
    vector<string> grid(m, string(m, '.'));
    for(int i=0; i<m; ++i){
        for(int j=0; j<min(k,m); ++j){
            if(n > 0){
                grid[i][(i+j)%m] = '#';
                -- n;
            }
        }
    }

    cout << m << endl;
    for(int i=0; i<m; ++i)
        cout << grid[i] << endl;

    return 0;
}