/**
  * This program will compute the arithmetic average for a set of exam scores .
  * Any negative value will be used as a sentinel
  *
  * @author Anthony Larrain
  */


import java.text.DecimalFormat;
import java.util.Scanner;

class AverageExamScore {
	public static void main( String [] args ) {
		// declare and initialize primitive variables
		int sum = 0, count = 0;

		// declare and create a Scanner object
		Scanner input = new Scanner(System.in);

		System.out.println("Enter first score ( enter a negative number to quit)");
		int score = input.nextInt();

		while (score > -1){
			sum += score;
			++count;
			System.out.println("Enter next score ( enter a negative number to quit)");
			score = input.nextInt();
		}

		if(count != 0){
			double average = sum / (double) count;
			DecimalFormat fmt = new DecimalFormat("0.00");
			System.out.println("The average is :  " + fmt.format(average));
		}else{
			System.out.println("No scores entered");
		}
	}
}