//a=abc/100;
//b=abc/10;
//b=b%10;
//c=abc%100;
//c=c%10;

#include<bits/stdc++.h>
using  namespace std;
bool ss(int n)
{
    bool r=true;
    if(n<2)
    r=false;
    else
    {
        for(int i=2;i<=sqrt(n);i++)
        {
            if(n%i==0)
            {
                r=false;
                break;
            }
        }
    }
    return r;
 } 
int main()
{
	cout<<"11"<<endl;
	int a,c;
    for(int i=100;i<1000;i++)
    {
    	a=i/100%10;
    	c=i%10;
        if(ss(i)&&ss(i%100)&&ss(i%10)&&a==c)
        {
            cout<<i<<endl;
        }
    }
    return 0;
}
/**************************************************************
	Problem: 1142
	User: chenzhuo1
	Language: C++
	Result: Wrong Answer
****************************************************************/