import java.util.*;
public class Main {
	public static void main(String[] args)
	{
		try (Scanner sc = new Scanner(System.in)) {
			int a=sc.nextInt();
			int b=sc.nextInt();
			for(int i=a;i<=b;i++)
			{
				if(i>=5&&i<10)//1
				{
					if(chek(i)==false)
						System.out.println(i);
				}
				else if(i<100)//2
				{	if(i%10==i/10&&chek(i)==false)
						System.out.println(i);
				}
				else if(i<1000)//3
				{
					if(i%10==i/100&&chek(i)==false)
						System.out.println(i);
				}
				else if(i<10000)//
				{
					if(i%10==i/1000&&i%1000/100==i%100/10&&chek(i)==false)
						System.out.println(i);
				}
				else if(i<100000)
					if(i%10==i/10000&&i%100/10==i%10000/1000&&chek(i)==false)
						System.out.println(i);
				else if(i<1000000)
					if(i%10==i/100000&&i%100/10==i%100000/10000&&i%1000/100==i%10000/1000&&chek(i)==false)
						System.out.println(i);
				else if(i<10000000)
					if(i%10==i/1000000&&i%100/10==i%1000000/100000&&i%1000/100==i%100000/10000&&chek(i)==false)
						System.out.println(i);
				else if(i<100000000)
					if(i%10==i/10000000&&i%100/10==i%10000000/1000000&&i%1000/100==i%1000000/100000&&i%10000/1000==i%100000/10000&&chek(i)==false)
						System.out.println(i);
			}
		}
		
		
	}
	
	public static boolean chek(int b)
	{
		boolean k=false;
		for(int i=2;i<=Math.sqrt(b);i++)
		{
			if(b%i==0)
				{k=true;
				return k;}
		}
		return k;
	}
}