#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <algorithm>
#include <bitset>
#include <climits>
#include <cmath>
#include <cstring>
#include <deque>
#include <forward_list>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;
typedef long long ll;
typedef pair<int, int> P;
typedef bitset<16> BS;

const ll MOD = 1E+09 + 7;
const ll INF = 1E18;
const int MAX_N = 1000;

int N, K;

char ans[MAX_N + 1][MAX_N + 1];

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

    cin >> N >> K;

    int p = N / (K * K), r = N % (K * K);
    fill(ans[1], ans[N + 1], '.');
    for (int c = 0; c < p; c++) {
        for (int i = 1; i <= K; i++) {
            for (int j = 1; j <= K; j++) {
                ans[c * K + i][c * K + j] = '#';
            }
        }
    }
    int sr = 0;
    while (sr * sr <= r) {
        sr++;
    }
    sr--;
    for (int i = 1; i <= sr; i++) {
        for (int j = i; j <= sr; j++) {
            if (p * K + (i - 1) + sr + j <= N) {
                ans[(p - 1) * K + i][(p - 1) * K + j] = '#';
            }
        }
    }

    /*
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            cout << "i = " << i << ", j = " << j << ", dp = " << dp[i][j] << "\n";
        }
    }
    */

    int M = p * K + sr;
    cout << M << "\n";
    for (int i = 1; i <= M; i++) {
        for (int j = 1; j <= M; j++) {
            cout << ans[i][j];
        }
        cout << "\n";
    }

    return 0;
}