/***************************************************
Sum of numbers

Write a program that reads in positive integers from 
the user, each separated by a space, and the whole 
terminated by a negative number (e.g. 3 22 10 -2),
and returns the sum of the numbers entered (not
including the terminated negative number!).
***************************************************/
#include <iostream>
using namespace std;

int main()
{
  // initialization
  cout << "Enter numbers separated by spaces"
       << " and terminated with a negative number."
       << endl;
  int sum, k;
  sum = 0;
  cin >> k;

  // Loop while the user enters more data
  while (k >= 0)
  {
    sum = sum + k;
    cin >> k;
  }

  // write out result
  cout << "The sum is " << sum << endl;

 return 0;
}