#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,m;
    cin>>n>>m;
    for(int i=n;i<=m;i++){
        int c=1;
        int w=i,s=0;
		while(w!=0){
			s=s*10+w%10;
			w/=10;
		}
        for(int j=2;j*j<=i;j++){
            if(i%j==0){c=0;break;}
        }
        if(c&&s==i) cout<<i<<endl;
    }
}