#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,b=-1;
    bool a=0;
    cin>>n;
    for(int i=0;i<n;i++){
        if(a)
            b--;
        else
            b++;
        for(int j=0;j<n;j++)
            if(j==n/2-b||j==n/2+b)
                cout<<"#";
            else
                cout<<".";
        if(b>=n/2)
            a=1;
        cout<<endl;
    }
    return 0;
}