#include <bits/stdc++.h>

using namespace std;

using ll = long long;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, K;
    cin >> n >> K;
    
    int m = (n + K - 1) / K;
    if (n < K * K) {
        for (int i = 1; i <= K; i++) {
            if (n <= i * i) {
                m = i;
                break;
            }
        }
    }

    int num = min(K, m);
    cout << m << "\n";
    for (int i = 0; i < m; i++) {
        string line(m, '.');
        for (int j = i; j < i + num; j++) {
            if (n > 0) {
                n--;
                line[j % m] = '#';
            }
        }
        cout << line << "\n";
    }
    return 0;
}