#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

int main(){
int N,K; cin >> N >> K;
  int M = (int)ceil(sqrt((double)N));
  M = max(M, (int)ceil((double)(N/K)));
  
  cout << M << endl;
  
  vector<vector<char>> S(M,vector<char>(M,'.'));
  int c = N; int pos = 0;
  for(int i = 0; i < M; i++){
    //i行目を完成させる
   for(int j = pos; j < min(pos+K,M); j++){
     S[i][j] = '#';}
    
    pos += K; pos %= M;}
  
  for(int i = 0; i < M; i++){
    for(int j = 0; j < M; j++){
      cout << S[i][j];}
    cout << endl;
  }
  return 0;}