#include <iostream>
#include <vector>
using namespace std;
int main(){
    int n,k;cin>>n>>k;
    int m = n;
    vector<int> ans;
    int ansm = 0;
    while(n>0){
        while(n-(k-1)*(k-1) <= 0)k--;
        n-=k*k;
        ans.push_back(k);
        ansm+=k;
    }
    cout << ansm << endl;
    int nw = 0;
    int ind = 0;
    int indnw = 0;
    for(int i = 0; ansm > i; i++){
        for(int j = 0; ansm > j; j++){
            if(nw <= j && j < nw+ans[ind] && m){
                cout << "#";m--;
            }else{
                cout << ".";
            }
        }
        cout << endl;
        indnw++;
        if(indnw == ans[ind]){
            ind++;
            nw += indnw;
            indnw = 0;
        }
    }
}