/* 9/23/2019
 
 */
import java.util.Scanner;

/** Problem: read in and print out a number of test grades 
  */
public class CountingAndSumming {
  
  public static void main(String[] args) { 

      Scanner scanner = new Scanner(System.in);
      // this loop uses a sentinel value (e.g. -1) and a structured read loop
      System.out.println("Enter a grade, -1 to finish: ");
      double grade = scanner.nextDouble();
      int count=0; // initialize count to ZERO outside of loop
      double sum=0.0; // initialize sum to ZERO outside of loop
      while(grade!=-1){      
           System.out.println("Grade " + grade);
           sum+=grade; // add the grade to the sum
           count++; // increment count
           System.out.println("Enter a grade, -1 to finish: ");
           grade = scanner.nextDouble();
      }
      // fall out of loop count will hold the number of times loop iterated
      System.out.println("count = " + count + " Total grades is: " + sum
                        + " Average = " + sum/count);
      scanner.close();
  }
}