#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<iostream>
#include<queue>
#include<vector>
#include <bitset>
#include<cmath>
using namespace std;
#define INF 110000000000
#define MOD 1000000007
typedef long long ll;
typedef pair<ll,int> P;



int main(){
  int N,K,count=0;
  cin>>N>>K;
  cout<<(N+K-1)/K<<endl;
  int M=(N+K-1)/K;
  for(int i=0;i<M;i++){
    for(int j=0;j<M;j++){
      
      if(i<=j && j<i+K || j<(i+K)%M && i+K>M){
        if(count<N){
          cout<<"#";
          count++;
        }else cout<<"."; 
      }else cout<<".";
    }
    cout<<endl;
  }
}