#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cassert>
#include <cstdint>
#include <iostream>
#include <iomanip>
#include <string>
#include <stack>
#include <queue>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include <numeric>
#include <bitset>

using namespace std;

using ll =  long long;
using Pll = pair<ll, ll>;
using Pii = pair<int, int>;

constexpr ll MOD = 1000000007;
constexpr long double EPS = 1e-10;
constexpr int dyx[4][2] = {
    { 0, 1}, {-1, 0}, {0,-1}, {1, 0}
};

int main() {
    std::ios::sync_with_stdio(false); cin.tie(nullptr);
    int n, k;
    cin >> n >> k;
    int n_lines = 0, n_black = 0;
    while(n_black < n) {
        n_lines += k;
        n_black += k*k;
    }

    vector<vector<char>> a(n_lines, vector<char>(n_lines, '.'));
    int cnt = 0;
    for(int i=0;i<n_lines;++i) {
        for(int j=i/k*k;j<i/k*k+k;++j) {
            a[i][j] = '#';
            ++cnt;
            if(cnt == n) break;
        }
        if(cnt == n) break;
    }

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