#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define LLINF 9223372036854775807
#define MOD ll(1e9+7)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cerr<<#x<<": "<<x<<endl

int main(){
    ll n, k;
    cin >> n >> k;

    ll m = 0;
    ll black = 0;
    while(n > black){
        for(int i = 1; i <= k; i++){
            m++;
            black += i*i-(i-1)*(i-1);
            if(n <= black){
                break;
            }
        }
    }
    cout << m << endl;
    ll cnt = 0;
    for(int i = 0; i < m; i++){
        for(int j = 0; j < m; j++){
            if(i/k*k <= j && j < i/k*k+k && cnt < n){
                cout << "#";
                cnt++;
            }else{
                cout << ".";
            }
        }
        cout << endl;
    }

    return 0;
}