#include<bits/stdc++.h>
using namespace std;
int huiwen(int n){
    int t=0;
    while(n!=0)
    {
        t=t*10+n%10;
        n=n/10;
    }
    return t;
}
bool sushu(int n){
    bool r=true;
    for(int i=2;i<=sqrt(n);i++){
        if (n%i==0){
            r=false;
        }
    }
    if(n<=1){
        r=false;
    }
    return r;
}
int main()
{
    for(int i=10;i<=1000;i++)
    {
        if(sushu(i)==true&&huiwen(i)==i)
        {
            cout<<i<<endl;
        }
    }
    return 0;
}
/**************************************************************
	Problem: 1142
	User: luyanchen
	Language: C++
	Result: Accepted
	Time:5 ms
	Memory:2072 kb
****************************************************************/