#pragma GCC optimize("O3")
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
#include <bitset>
using namespace std;

using ll = long long;
using P = pair<int, int>;
using T = tuple<int, int, int>;

template <class T> inline T chmax(T &a, const T b) {return a = (a < b) ? b : a;}
template <class T> inline T chmin(T &a, const T b) {return a = (a > b) ? b : a;}

constexpr int MOD = 1e9 + 7;
constexpr int inf = 1e9;
constexpr long long INF = 1e18;
constexpr double pi = acos(-1);
constexpr double EPS = 1e-10;

int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    int n, k; cin>>n>>k;

    vector<vector<char>> grid(1010, vector<char>(1010, '.'));

    int cnt = 0;
    int hw;
    for(; ; cnt++){
        if(n - k * k < 0){
            for(int x=1; ; x++){
                if(n <= x * x){
                    hw = cnt * k + x;
                    for(int i=cnt*k; i<cnt*k+x; i++){
                        for(int j=cnt*k; j<cnt*k+x; j++){
                            if(0 < n) grid[i][j] = '#';
                            n--;
                        }
                    }
                    goto END;
                }
            }
        }
        else{
            hw = (cnt + 1) * k;
            for(int i=cnt*k; i<(cnt+1)*k; i++){
                for(int j=cnt*k; j<(cnt+1)*k; j++){
                    grid[i][j] = '#';
                    n--;
                }
            }

            if(n == 0) goto END;
        }
    }

    END:;

    cout << hw << endl;
    for(int i=0; i<hw; i++){
        for(int j=0; j<hw; j++){
            cout << grid[i][j];
        }
        cout << endl;
    }

    return 0;
}