#include "bits/stdc++.h"
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;

using ll = long long;
const ll MOD = 1e9 + 7;

int main() {
    int N, K, M, c = 0;
    cin >> N >> K;
    M = (N + K - 1) / K;
    rep(i, N + 1) {
        if (i * i >= N) {
            M = max(i, M);
            break;
        }
    }
    cout << M << endl;
    rep(i, M) {
        rep(j, M) {
            if ((i + j) % M < K && c < N) {
                cout << "#";
                c++;
            } else cout << ".";
        }
        cout << endl;
    }
}