include <stdio.h>
int a, b, i, y, p, c, w, qw=0,mn,qwe=1,qwr=0,qwer=0,po,sa,v,zb,cb,nmb;
int f(int y)
{
	int z; nmb = y;
	for (z = 2; z <= nmb/2; z++)
	{
		if (nmb % z == 0)
		{
			y = 1; break;
		}
		else
			y = 0;	
	}
	return y;
}
int nm(int v)
{
	po = v;
	int a[8];
	qw = 0;
	while (v >= 10)
	{
		p = v;
		v = v / 10; c = v * 10;
		w = p - c;
		a[qw] = w;
		qw = qw + 1;
	}
	a[qw] = v;
	mn = qw;
	qwe = 1; qwr = 0;
		for (qw = mn; qw >= 0; qw--)
		{
			qwr = qwe * a[qw] + qwr;
			qwe = qwe * 10;
		}
		if (qwr == po)
			v = 1;
		else
			v = 0;
	return v;
}
int main()
{
	scanf("%d", &a);
	scanf("%d", &b);
	if (b > 9989899) 
		b = 9989899;
	for (i = a; i >= a && i <= b; i++)
	{		
		{
			 sa = nm(i);
			if (sa != 1)
				continue;			
			zb = f(i);
			if (zb != 0)
				continue;	
				printf("%d\n", i);
		}		
	}
}