#include<bits/stdc++.h>
using namespace std;
bool huiwen(int x)
{
	//cout<<x<<"run in huiwen"<<endl;
	int s=x;
	int a[100];
	int wei=0;
	int cnt=0;
	while(x!=0)
	{
		cnt++;
		a[cnt]=x%10;
		wei++;
	}
	for(int i=1;i<=wei/2;i++)
	{
		if(a[i]!=a[wei]) return false;
	
		wei--;	
	}
	return true;
	
}
bool zhishu (int x)
{
	//cout<<x<<"run in zhishu"<<endl;
	if(2>x) return false;
	//cout<<"enter";
	for(int i=2;i*i<=x;i++)
	{
		if(x%i==0) return false;
	}
	cout<<x<<endl;
	return true;
}
int main()
{
	
	int a,sb=0;
	cin>>a;
	for(int i=11;i<=a;i+=2)
	{
		cout<<11<<endl;
		if(zhishu(i)&&huiwen(i)) sb++;
	}
	//cout<<"over";
	cout<<sb;
	return 0;
}