#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <chrono>
#define _USE_MATH_DEFINES
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;

#define int long long
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-8;
const int MOD = 1000000007; // 998244353;
const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
/*-------------------------------------------------*/
signed main() {
  cin.tie(nullptr); ios::sync_with_stdio(false);
  // freopen("input.txt", "r", stdin);

  int n, k; cin >> n >> k;
  int block = n / (k * k);
  int nokori = 0;
  while (nokori * nokori < n - block * k * k) ++nokori;
  int m = block * k + nokori;
  vector<vector<char> > a(m, vector<char>(m, '.'));
  REP(i, block) {
    FOR(y, k * i, k * i + k) FOR(z, k * i, k * i + k) a[y][z] = '#';
  }
  n -= block * k * k;
  FOR(i, k * block, m) FOR(j, k * block, m) {
    if (n > 0) {
      a[i][j] = '#';
      --n;
    }
  }
  cout << m << '\n';
  REP(i, m) {
    REP(j, m) cout << a[i][j];
    cout << '\n';
  }
  return 0;
}