#include <bits/stdc++.h>
using namespace std;
using lint = long long;
template<class T = int> using V = vector<T>;
template<class T = int> using VV = V< V<T> >;

int main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  int m, k; cin >> m >> k;
  int n = 1;
  while (n * min(n, k) < m) ++n;
  V<string> res(n, string(n, '.'));
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < min(n, k); ++j) {
      if (m) {
        res[i][(i + j) % n] = '#';
        --m;
      }
    }
  }
  cout << n << '\n';
  for (const auto& e : res) cout << e << '\n';
}