import java.util.Scanner;

/** 解析

 * 此题我是分为上下、中间两个部分算的，先算好中间带小数点的有几行，然后打印，接着

 * 打印中间行。

 *

 */

public class 打印大X {

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);

        while (input.hasNext()) {

            int count = 0;

            int m = input.nextInt();

            int n = input.nextInt();

            //求出中间部分有小数点的图形有多少行

            count = m % 2 == 0 ? (n - m - 1) / 2 : (n - m) / 2;

            String str[] = new String[count + (m / 2) + 1];

            for (int i = 0; i < count; i++) {

                str[i] = "";

                for (int j = 0; j < i; j++) {

                    str[i] += ".";

                }

                for (int j = 0; j < m; j++) {

                    str[i] += "*";

                }

                //中间

                if (m % 2 == 0) {

                    for (int j = 0; j < (count - 1 - i) * 2 + 2; j++) {

                        str[i] += ".";

                    }

                } else {

                    for (int j = 0; j < (count - 1 - i) * 2 + 1; j++) {

                        str[i] += ".";

                    }

                }

                for (int j = 0; j < m; j++) {

                    str[i] += "*";

                }

                for (int j = 0; j < i; j++) {

                    str[i] += ".";

                }

            }

            //中间部分

            int res = (count + (m / 2)) * 2 + m;//算出图形的宽度

            int index = count;

            for (int i = 0; i < (m / 2) + 1; i++) {

                str[index]="";

                //从count开始打印前面的小数点

                for (int j = 0; j < count + i; j++) {

                    str[index] += ".";

                }

                for (int j = 0; j < res - (count + i) * 2; j++) {

                    str[index] += "*";

                }

                for (int j = 0; j < count + i; j++) {

                    str[index] += ".";

                }

                index++;

            }

            for (int j = 0; j < str.length; j++) {

                System.out.println(str[j]);

            }

            for (int j = str.length - 2; j >= 0; j--) {

                System.out.println(str[j]);

            }

        }

    }

}