// IC210 section 4002
// 9 September 2009
//This program computes the sum of numbers entered by user
//We assume the user enters positive integers separated by space terminated by
//one negative number
//The negative number is just to signal the end of the input,
//the negative number is not part of sum
// Ex user input: 2 67 8 -5
// Example output: Sum is 77
#include <iostream>

using namespace std;

int main()
{

	//declare variables
	int sum; //to hold the sum 
	int readnumber; //to hold one number from the user

	//Ask user for numbers
	cout << "Enter positive integers separated by space and terminated by a negative integer " << endl;

	//initialize variables -- very important
	sum = 0;
	cin >> readnumber; //read first number given by user

	//as long as the number is positive, add it to the sum and
	//read another number from the display
	while(readnumber >= 0)
	{
		sum = sum + readnumber;
		cin >> readnumber;
	}

	//output result
	cout << "Sum is " << sum;

	return 0;
}