import javax.swing.*;

public class Unit6Dem2
{
   public static void main(String[] args)
   {
       //declare variables
       String input;
       double mark, average, sum;
       int count, answer;

       sum = 0;
       count = 0;

       //ask user to enter an percentage mark atleast once.
       do
       {
          input = JOptionPane.showInputDialog("Please enter a percentage mark");
          mark = Double.parseDouble(input);  //stored as a double to get a more precise answer

             //store the value of the current sum to the user's last input.
          sum = sum + mark;

        //ask user if they want to enter another integer
          answer = JOptionPane.showConfirmDialog(null, "Input another percentage mark?",
                  "???", JOptionPane.YES_NO_OPTION);//stating my dialog box
       count++;

        //get the average of the sum by dividing it by how many integers the user inputted
       average = sum / count;

       }while (answer == JOptionPane.YES_OPTION);

        //show user how many marks they've entered and what the average of the numbers they put in.
       JOptionPane.showMessageDialog(null, "You have entered " + count + " percentage marks\nThe average is " + average);

       System.exit(0);

   }
}