#include "bits/stdc++.h"
using namespace std;

int main(){
    int n,k;
    cin >> n >> k;
    int m = n / (k*k) * k;
    int r = n / (k*k);
    int more = 0;
    for(int i = 0; i < k; i++){
        if(r <= i*i) more = i;
        else break;
    }
    m += more;
    cout << m << endl;
    for(int i = 0; i < m; i++){
        for(int j = 0; j < m; j++){
            if(n != 0 && i/k == j/k){
                cout << '#';
                n--;
            }else{
                cout << '.';
            }
        }
        cout << endl;
    }
}