Laivanupotus

import java.util.Scanner;

public class Laivanupotus {

	public static void main(String[] args) {
		int n = new Scanner(System.in).nextInt();

		if (n<4){
			for (int y=0 ; y<n ; y++){
				for (int x=0 ; x<n ; x++){
					System.out.print(".");
				}
				System.out.println();
			}
		}
		else {

			for (int y=1 ; y<=n ; y++){
				for (int x=0 ; x<n ; x++){
					if ((x+y)%4 == 0){
						System.out.print("*");
					}
					else {
						System.out.print(".");
					}
				}
				System.out.println();
			}

		}
		
		
		
		
		
	}

}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED