Laivanupotus

import java.util.*;

public class laiva {
    public static void main(String[] args) {
	
        Scanner input = new Scanner(System.in);

		int n = input.nextInt();
		input.close();

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

		else {
		
		String[] rivi = new String[4];
		String[] alkurivi = new String[4];

		alkurivi[0] = "...*";
		alkurivi[1] = "..*.";
		alkurivi[2] = ".*..";
		alkurivi[3] = "*...";

		rivi[0] = "...*";
		rivi[1] = "..*.";
		rivi[2] = ".*..";
		rivi[3] = "*...";

		for (int k = 0; k < 4; k++) {
		 for (int i = 1; i < (n/4); i++) {
			rivi[k] = rivi[k] + alkurivi[k];
		  }
		 if ((n%4) > 0) rivi[k] = rivi[k] + alkurivi[k].substring(0, (n%4));
		}


		for (int y = 0; y < n; y++) {
		  System.out.println(rivi[(y%4)]);
		 }

		}
    }
}

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