#ifndef LOCAL
#include <bits/stdc++.h>

using namespace std;

#define debug(...) (void(0))
#else
#include "algo/debug.h"
#endif

void solve() {
    int N, K;
    cin >> N >> K;
    auto check = [&](int L) -> bool {
        int Lq = L / K, Lr = L % K;
        return K * K * Lq + Lr * Lr <= N;
    };
    int lo = 1, hi = 1001;
    while (hi - lo > 1) {
        int mi = (lo + hi) >> 1;
        (check(mi) ? lo : hi) = mi;
    }
    cout << lo << endl;
    vector<string> ans(lo, string(lo, '.'));
    int cur = 0;
    [&]() -> void {
        while (N) {
            for (int i = cur; i < min(lo, cur + K); i++) {
                for (int j = cur; j < min(lo, cur + K); j++) {
                    ans[i][j] = '#';
                    N--;
                    if (!N) return;
                }
            }
            cur += K;
        }
    }();
    for (int i = 0; i < lo; i++) cout << ans[i] << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int tt = 1;
    // std::cin >> tt;
    while (tt--) {
        solve();
    }
}