# include <stdio.h>
# include <malloc.h>

int isprime(int i)
{
	int j;
    for (j=2; j<=i; ++j)	
	{
		if (i%j == 0 && i != j)
			return 0;
	    else  if (i == j)
			return 1;
	}

}

int huiwen(int i)
{
	int k, l = 0;
     for (k=i; k; k/=10)
		l = l*10 + k%10;
	if (l == i)
	   return 1;
	else
	   return 0;
}

int main(void)
{
     long a, b, i ;
	 
	scanf("%ld %ld", &a, &b);
	
	for (i=a; i<=b; ++i)
	{
	    if(isprime(i)&&huiwen(i))
			printf("%d\n", i);
	}

    return 0;

本来是用函数写的，但是超时了7个测试点！！