#include "pch.h"
#include <iostream>
using namespace std;
int main() {
	int a, b;
	for (;;) {
		cin >> a >> b;
		if (a == 0 && b == 0) { break; }
	}
	for (int i = 0; i < a; i++){
		for (int j = 0; j < b; j++) {
			if (i + j == 2) { cout << '#'; }
			else { cout << '.'; }
		}
		cout << endl;
	}
}
