import java.io.PrintStream;
import java.util.Scanner;
import java.util.List;
import java.util.LinkedList;

public class Example6
{
    public static void main(String[] args)
    {
	Scanner input = new Scanner(System.in);
	PrintStream output = System.out;

	int days = 0;
	do
	{
	    try
	    {
		output.print("Enter number of days (days > 0): ");
		days = Integer.parseInt(input.nextLine());
	    }
	    catch (NumberFormatException e) {}
	}
	while (days <= 0);

	List<Joke> list = new LinkedList<Joke>();
	for (int i = 0; i < days; i++)
	{
	    list.add(Joke.getRandom()); // getRandom may return null
	}

	int rate = 0;
	int count = 0;
	for (int i = 0; i < days; i++)
	{
	    Joke joke = list.get(i);
	    if (joke != null)
	    {
		rate += joke.getRate();
		count++;
	    }
	}
	if (count != 0)
	{
	    output.println("Average rate: " + rate / (double) count);
	}
	else
	{
	    output.println("No jokes");
	}
    }
}