// This program illustrates a sentinel controlled while loop.
// Write a program that calculates the average of an unknown number of positive integers.
// The program is to stop when a negative integer is entered.

#include <iostream>
using namespace std;

int main()
{
	int value, count, sum;

	count = 0;	
	cout << "Please enter positive integers, a -1 to stop" << endl;

	cin >> value;		// initialize
	while (value != -1)	// test 
	{
		sum += value;
		count++;		
		cin >> value;	// modify 
	}

	cout << " The average is " << (double)sum / count << endl;
}