#include <iostream>
#include <vector>
#include <cassert>
#include <algorithm>
#include <functional>
#include <cmath>
using namespace std;
int main(){
    int n,k;cin >> n >> k;
    int ans;
    if(n==1){
        cout<<1<<endl;
        cout<<'#'<<endl;
        return 0;
    }
    if(n%k==0){
        if((int)sqrt(n)==(float)sqrt(n)){
            ans=max(n/k,(int)sqrt(n));
            cout<<ans<<endl;
        }else{
            cout<<max(n/k,(int)sqrt(n)+1)<<endl;
            ans=max(n/k,(int)sqrt(n)+1);
        }
    }else{
        if((int)sqrt(n)==(float)sqrt(n)){
            ans=max(n/k+1,(int)sqrt(n));
            cout<<ans<<endl;
        }else{
            cout<<max(n/k+1,(int)sqrt(n)+1)<<endl;
            ans=max(n/k+1,(int)sqrt(n)+1);
        }
    }
 //   int j=0;
    vector<vector<bool>> reg(ans,vector<bool>(ans));
    int f=0;
    for(int i=0;i<ans;i++){
        int g=f;
        for(int j=0;j<k;j++){
            reg[i][f]=true;
            f++;
            n--;
         //   cout<<i<<" "<<f<<endl;
            if(f==ans)f=0;
            if(f==g)break;
            if(n==0)break;
          //  cout<<n<<endl;
        }
        if(n==0)break;
    }
    for(int i=0;i<ans;i++){
        for(int j=0;j<ans;j++){
            if(reg[i][j]){
                cout<<'#';
            }else{
                cout<<'.';
            }
        }
        cout<<endl;
    }
}