#include <bits/stdc++.h>
using namespace std;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    long long N, K;
    cin >> N >> K;
    if (N == 0) {
        cout << 1 << "\n.\n";
        return 0;
    }
    long long M = (N + K - 1) / K;
    long long q = sqrt(N);
    while (q * q < N) q++;
    while ((q - 1) * (q - 1) >= N) q--;
    M = max(M, q);
    cout << M << "\n";
    long long c = 0;
    long long r = N;
    for (long long i = 0; i < M; i++) {
        string s(M, '.');
        long long x = min(K, r);
        for (long long j = 0; j < x; j++) {
            s[(c + j) % M] = '#';
        }
        c = (c + x) % M;
        r -= x;
        cout << s << "\n";
    }
    return 0;
}