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;

    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 < min(k,r); 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;
    }
}