#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) ? hi : lo) = mi;
        }
        cout << hi << endl;
        vector<string> ans(hi, string(hi, '.'));
        int cur = 0;
        [&]() -> void {
            while (N) {
                for (int i = cur; i < min(hi, cur + K); i++) {
                    for (int j = cur; j < min(hi, cur + K); j++) {
                        ans[i][j] = '#';
                        N--;
                        if (!N) return;
                    }
                }
                cur += K;
            }
        }();
        for (int i = 0; i < hi; 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();
    }
}