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


signed main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(20);
    
    ll n,k;
    cin>>n>>k;
    ll t = n/(k*k);
    ll m = t*k;
    t*=k*k;
    ll s = n-t;
    s = sqrt(s);
    if(s*s != n-t) s++;
    m += s;
    cout << m << endl;
    char c[m][m];
    ll cnt=0;
    for(ll i=0;i<m;i++){
        for(ll j=0;j<m;j++){
            if(cnt<n && j >= i/k * k && j< i/k *k+ k){
                c[i][j] = '#';
                cnt++;
            }
            else c[i][j] = '.';
            cout << c[i][j];
        }
        cout << endl;
    }

}