这是代码

#include<bits/stdc++.h>
using namespace std;
int judge(int i){
	int a[10],l=1,q=i;
	while(q/10){
		a[l]=q%10;
		q/=10;
		l++;
	}
	a[l]=q;
	int n;
	if(l%2==0) n=l/2;
	else n=(l-1)/2;
	int t=1;
	for(int j=1;j<=n;++j){
		if(a[j]!=a[l-j+1]){
			t=0;
			break; 
		}
	}
	if(t){
		int p=0;
		for(int j=2;j<=sqrt(i);++j){
			if(i%j==0) p++;
		}
		if(!p) return 1;
	}
	return 0;
}
int main(){
	int a,b;
	cin>>a>>b;
	for(int i=a;i<=b;++i){
		if(i%6==0){
			if(judge(i-1)) cout<<i-1<<endl;
			if(judge(i+1)) cout<<i+1<<endl;
		}
	}
}