#include "bits/stdc++.h"

using namespace std;

void solve()
{
    int n, k;
    cin >> n >> k;
    int m = (n + k - 1) / k;
    if (m * m < n)
    {
        m = sqrt(n);
        if (m * m < n)
            m++;
    }
    cout << m << endl;
    int l = 0, r = min(k, m);
    for (int _ = 0; _ < m; _++)
    {
        for (int i = 0; i < m; i++)
        {
            if (n && ((l <= i && i < r) || (l <= i + m && i + m < r)))
            {
                cout << '#';
                n--;
            }
            else
            {
                cout << '.';
            }
        }
        l++, r++;
        cout << '\n';
    }
}

int main()
{
    solve();
    return 0;
}