import java.io.IOException;
import java.util.Scanner;
public class Main {

	public static void main(String[] args) throws Exception	{
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	}

} import java.io.IOException; IOException java.io import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) throws Exception	{
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	}

} Main public static void main(String[] args) throws Exception	{
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	} main {
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int a a b b c c d d e; e a=1 a 1 b=1 b 1 e=1 e 1 while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           } a!=0||b!=0 a!=0 a 0 b!=0 b 0 {
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           } a = sc.nextInt() a sc.nextInt() sc.nextInt sc b = sc.nextInt() b sc.nextInt() sc.nextInt sc c=1 c 1 d=1 d 1 if(e!=1){
        		   System.out.println();
        	   } e!=1 e 1 {
        		   System.out.println();
        	   } System.out.println() System.out.println System.out System System.out while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   } c<=a c a {
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   } while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   } d<=b d b {
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   } if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   } (d+c)%2==0 (d+c)%2 (d+c) d c 2 0 {
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   } if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   } d!=b d b {
        					   System.out.print("#");
        				   } System.out.print("#") System.out.print System.out System System.out "#" {
        					   System.out.println("#");
        				   } System.out.println("#") System.out.println System.out System System.out "#" if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   } (d+c)%2==1 (d+c)%2 (d+c) d c 2 1 {
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   } if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   } d!=b d b {
        					   System.out.print(".");
        				   } System.out.print(".") System.out.print System.out System System.out "." {
        					   System.out.println(".");
        				   } System.out.println(".") System.out.println System.out System System.out "." d=d+1 d d+1 d 1 d=1 d 1 c=c+1 c c+1 c 1 c=1 c 1 e=e+1 e e+1 e 1 String[] args args public class Main {

	public static void main(String[] args) throws Exception	{
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	}

} public class Main {

	public static void main(String[] args) throws Exception	{
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	}

} Main
import java.io.IOException;
import java.util.Scanner;
public class Main {

	public static void main(String[] args) throws Exception	{
		// TODO ?????????????????????????????????????????????
           Scanner sc = new Scanner(System.in);
           int a,b,c,d,e;
           a=1;b=1;e=1;
           while(a!=0||b!=0){
        	   a = sc.nextInt();
        	   b = sc.nextInt();
        	   c=1;d=1;
        	   if(e!=1){
        		   System.out.println();
        	   }
        	   while(c<=a){
        		   while(d<=b){
        			   if((d+c)%2==0){
        				   if(d!=b){
        					   System.out.print("#");
        				   }else{
        					   System.out.println("#");
        				   }
        			   }
        			   if((d+c)%2==1){
        				   if(d!=b){
        					   System.out.print(".");
        				   }else{
        					   System.out.println(".");
        				   }
        			   }
        			   d=d+1;
        		   }
        		   d=1;
        		   c=c+1;
        	   }
        	   c=1;
        	   e=e+1;
           }
	}

}