#include<bits/stdc++.h> using namespace std; bool isPalindromes(int a){ int t = a,s = 0; while(t > 0) s = s * 10 + t % 10, t /= 10; if(a == s) return 1; return 0; } bool isPrime(int a){ for(int i = 2;i * i <= a;i ++) if(a % i == 0) return 0; return 1; } int main(){ int a, b; scanf("%d%d", &a, &b); if(b > 10000000)b = 9999999; for(;a <= b;a ++) if(isPalindromes(a)) if(isPrime(a)) printf("%d\n", a); return 0; }