打印飞镖

import java.util.*;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            int n = sc.nextInt();
            StringBuilder sb = new StringBuilder();
            int m = 2*n;
            while(m-- > 0) sb.append(" ");
            sb.append("*");
            for(int i = 0; i <= n; ++i){    //打印上半部分
                System.out.println(sb);
                sb.delete(0, 2);
                sb.append("*");
            }
            for(int i = 0; i < n; ++i){    //打印下半部分
                sb.insert(0, "  ");
                System.out.println(sb);
                sb.deleteCharAt(sb.length() - 1);
            }
        }
    }
}