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

int main() {
    ll n,k;
    std::cin >> n>>k;
    
    ll r = (n+k-1)/k;
    
    if(r<k){
        ll r = ceil(sqrt(n));
        std::cout << r << std::endl;
        for (int i = 0; i < r; i++) {
            for (int j = 0; j < r; j++) {
                if(n>0){
                    std::cout << "#";
                    n--;
                }else{
                    std::cout << ".";
                }
            }
            std::cout << std::endl;
        }
        
        return 0;
    }
    
    std::cout << r << std::endl;
    vector<vector<ll>> ans(r,vector<ll>(r,0));
    ll offset = 0;
    for (int i = 0; i < r; i++) {
        for (int j = 0; j < k; j++) {
            if(n>0){
                ans[i][(j+offset)%r]=1;
                n--;
            }
        }
        offset++;
    }
    for (int i = 0; i < r; i++) {
        for (int j = 0; j < r; j++) {
            std::cout << (ans[i][j]==1 ? "#":".");
        }
        std::cout << std::endl;
    }
}