#include <iostream>
#include <cmath>

using namespace std;

int main()
{
    int N, K;
    cin >> N >> K;
    int k = K * K;
    int m = (N / k) * K;
    int r = N % k;
    int d = 0;
    while (d * d < r)
    {
        d++;
    }
    int M = m + d;
    cout << M << endl;
    int cnt = 0;
    for (int i = 0; i < M; i++)
    {
        for (int j = 0; j < M; j++)
        {
            if (i / K == j / K && cnt < N)
            {
                cout << '#';
                cnt++;
            }
            else
                cout << '.';
        }
        cout << endl;
    }
}