#include <bits/stdc++.h>
using namespace std;

int main(void){
    long long N, K; cin >> N >> K;
    long long N_tmp = N;
    long long cnt = 0;
    long long add_cnt = 1;
    long long n;
    for (n = 0; cnt < N; n++) {
        if (n % K == 0) {
            add_cnt = 1;
        } else {
            add_cnt += 2;
        }
        cnt += add_cnt;
    }

    cout << n << endl;
    vector<string> field;
    for (int i = 0; i < n; i++) {
        string s;
        for (int j = 0; j < n; j++) {
            if (i / K * K <= j && j < i / K * K + K && N > 0) {
                s += '#';
                N--;
            } else {
                s += '.';
            }
        }
        field.push_back(s);
    }
    
    for (int i = 0; i < field.size(); i++) {
        cout << field[i] << endl;
    }
    
    int sharp_cnt = 0;
    for (int i = 0; i < n; i++) {
        int cnt = 0;
        for (int j = 0; j < n; j++) {
            if (field[i][j] == '#') {
                cnt++;
                sharp_cnt++;
            }
        }
        assert(cnt <= K);
    }
    for (int i = 0; i < n; i++) {
        int cnt = 0;
        for (int j = 0; j < n; j++) {
            if (field[j][i] == '#') cnt++;
        }
        assert(cnt <= K);
    }
    assert(sharp_cnt == N_tmp);
}