/* -*- coding: utf-8 -*-
 *
 * 883.cc:  No.883 ぬりえ - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 1000;

/* typedef */

/* global variables */

bool flds[MAX_N][MAX_N];

/* subroutines */

/* main */

int main() {
  int n, k;
  scanf("%d%d", &n, &k);

  int kk = k * k, d = n / kk, r = n - d * kk;
  int l = 0;
  while (l * l < r) l++;
  //printf("l=%d, m=%d\n", l, m);

  if (r == k && d > 0) {
    l = k + 1, d--;
    for (int y = 0; y < l; y++)
      for (int x = 0; x < l; x++, r--) flds[y][x] = (y != x);
  }
  else 
    for (int y = 0; y < l && r > 0; y++)
      for (int x = 0; x < l && r > 0; x++, r--) flds[y][x] = true;

  for (int i = 0; i < d; i++)
    for (int y = 0; y < k; y++)
      for (int x = 0; x < k; x++) flds[y + l + i * k][x + l + i * k] = true;

  int m = l + d * k;
  printf("%d\n", m);
  for (int y = 0; y < m; y++) {
    for (int x = 0; x < m; x++) putchar(flds[y][x] ? '#' : '.');
    putchar('\n');
  }
  return 0;
}