#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	int x=n/2+1,y=x;
	for (int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)
		{
			if(abs(i-x)+abs(j-y)==x-1) //边缘判断
			{
				cout<<"#";
			}
			else
			{
				cout<<".";
			}
		}
		cout<<endl;
	}
	return 0;
}