#include "bits/stdc++.h"

using namespace std;

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

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