CH3 Emirps

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

/*
 * Tuenti Contest
 * Challenge 3 - Emirps
 * Author: Pedro Antonio Pardal Jimena
 * Email: [email protected]
 */

public class Emirps
{
    private static boolean esPrimo( long n )
    {
        if ( n == 1 )
            return false;
        else if ( n < 4 )
            return true;

        long m = (long) Math.sqrt( n );

        for ( long i = 2; i <= m; i++ )
        {
            if ( n % i == 0 )
                return false;
        }

        return true;
    }

    private static List<Long> primosHasta( long n )
    {
        List<Long> primos = new LinkedList<Long>();

        for ( long i = 1; i <= n; i++ )
        {
            if ( esPrimo( i ) )
                primos.add( i );
        }

        return primos;
    }

    private static long reverse( long n )
    {
        String strn = String.valueOf( n );
        StringBuffer b = new StringBuffer( strn );

        return Long.parseLong( b.reverse().toString() );
    }

    private static long sumaEmirps( List<Long> primos, long max )
    {
        long result = 0;
        for ( Long l : primos )
        {
            if ( l > max )
                break;

            long reversed = reverse( l );

            if ( l != reversed && primos.contains( reversed ) )
                result += l;
        }
        return result;
    }

    private static long procesaEmirps( String linea )
    {
        long n = 0;

        try
        {
            n = Long.parseLong( linea );
        }
        catch ( NumberFormatException e )
        {
        }

        if ( n > 2 )
        {
            long tope = (long) Math.pow( 10, Math.ceil( Math.log10( n ) ) );
            List<Long> primos = primosHasta( tope );

            return sumaEmirps( primos, n );
        }
        else
        {
            return 0L;
        }
    }

    public static void main( String[] args ) throws IOException
    {
        BufferedReader reader = new BufferedReader( new InputStreamReader( System.in ) );

        while ( reader.ready() )
        {
            String linea = reader.readLine();
            long result = procesaEmirps( linea );

            System.out.println( result );
        }
    }
}