/* This program calculates the total class average.
 * The grades are entered by the user. We do not have a determinate number of students.
 * We will keep reading until the user is done entering input.
 * To terminate the program, enter the end of file character (Ctrl+d)
 * This is also a demonstration of stepwise refinement.
 */
import java.util.Scanner;
class CalcAverage
{
	public static void main(String [] args)
	{
		Scanner input=new Scanner(System.in);
		//Step 1: Declare tghe variables
		double sum=0,average=0,studentCount=0,grade=0;
		
		//Step 2: User input
		//2.1 Prompt the user
		System.out.println("Enter the grades:");
		//2.2 Read the grade value
		do{
			grade=input.nextDouble();
			studentCount++; //every time we get a grade it means ther is one more student.
		//2.3 Add grade to sum
			sum = sum + grade; //running total
		}while(input.hasNext());
		/* hasNext() is a method of the Scanner class that will 
		 * return true if there in any input left on the Scanner.
		 * It returns false if all the input has been consumed.
		 */
		//Step 3: Calculate average
		average = sum/studentCount;
		
		//Step 4: Output
		System.out.println("the class average is : "+ average);
		
	}
}