#include <bits/stdc++.h>
using namespace std;
int main()
{
 int a,b,c=1,d=1;
 cin>>a>>b;
 int x[b-a+1],y[b-a+1];
 memset(x,0,sizeof(x));
 memset(y,0,sizeof(y));
 for(int i=a;i<=b;i++){
 bool o=0;
  for(int j=2;j<=i/2;j++){
   if(i%j==0){
    o=1;
    break;
   }
  }
  if(o) continue;
  x[c]=i;
  c++;
 }
 for(int i=1;i<=c;i++){
  int u=0,q=x[i];
  while(q>0){
   u=u*10+q%10;
   q=q/10;
  }
  if(u==x[i]){
   y[d]=x[i];
   d++;
  }
 }
 for(int i=1;i<=d;i++){
  cout<<y[i]<<endl;
 }
 return 0;
}