#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <deque>
#include <queue>
#include <array>
#include <set>
#include <map>
#include <cmath>
#include <algorithm>
#include <numeric>
#include <utility>
#include <tuple>
#include <functional>
#include <bitset>
#include <cstdint>
#include <cassert>
#include <random>

using namespace std;
using i64 = int64_t;
using i32 = int32_t;
template<class T, class U> void init_n(vector<T>& v, size_t n, U x) 
{ v = vector<T>(n, x); }
template<class T> void init_n(vector<T>& v, size_t n) { init_n(v, n, T()); }
template<class T> void read_n(vector<T>& v, size_t n, size_t o = 0) 
{ v = vector<T>(n+o); for (size_t i=o; i<n+o; ++i) cin >> v[i]; }
template<class T> void read_n(T a[], size_t n, size_t o = 0)
{ for (size_t i=o; i<n+o; ++i) cin >> a[i]; }
template<class T> T gabs(const T& x) { return max(x, -x); }
#define abs gabs

int main() {
  i64 n, k;
  cin >> n >> k;
  i64 bcnt = n / (k * k);
  i64 rest = n - k * k * bcnt;
  i64 rh = 0;
  for (; rh * rh < rest; ++rh);

  i64 m = bcnt * k + rh;

  cout << m << '\n';
  for (i64 i = 0; i < bcnt; ++i) {
    for (i64 l = 0; l < k; ++l) {
      for (i64 j = 0; j < m; ++j) {
        char c = '.';
        if (i * k <= j && j < (i + 1) * k) c = '#';
        cout << c;
      }
      cout << '\n';
    }
  }

  for (i64 i = 0; i < rh; ++i) {
    for (i64 j = 0; j < m; ++j) {
      char c = '.';
      if (j >= m - rh && rest > 0) {
        c = '#';
        --rest;
      }
      cout << c;
    }
    cout << '\n';
  }
  return 0;
}