package com.javarush.task.jdk13.task06.task0634;
import java.util.Scanner;
/*
Шахматная доска
*/
public class Solution {
public static char[][] array;
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt();
array = new char[a][a] ;
for(int i = 0; i < array.length;i++) {
for(int j = 0; j < array[i].length;j++) {
if((i + j) % 2 == 0) {
System.out.print('#');
}else {
System.out.print(' ');
}
}System.out.println();
}}}