#include<iostream>
#include<vector>
#include<map>
#include<string>
#include<cstring>
#include<bitset>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<cstdio>
#include<numeric>
#include<set>
#include<math.h>
using namespace std;

const int dx[4]={1,0,-1,0};
const int dy[4]={0,1,0,-1};

#define rep(i,x) for(int i=0;i<x;i++)
#define re(i,x,y) for(int i=x;i<y;i++)

long long INF=1e9;
const long long mod=2019;
#define ll long long

int main(){
    cin.tie(0); ios::sync_with_stdio(false);
    int n,k; cin>>n>>k;
    int num=1,x;
    if(n<k*k){
        while(num*num<n){
            num++;
        }
        x=num;
    }
    else{
        x=n/k;
    }
    cout<<x<<endl;
    vector<vector<char> >a(x,vector<char>(x,'.'));
    int tmp=0;
    rep(i,x){
        rep(j,x){
            if((i+j)%x<k&&tmp<n)a[i][j]='#',tmp++;
        }
    }
    rep(i,x){
        rep(j,x){
            cout<<a[i][j];
        }
        cout<<endl;
    }
    return 0;
}