#include <math.h>
#include <iostream>
using namespace std;

int main()
{
  double x, sum=0;
  cout << "Please input numerical values, ended by a <Control-D>" << endl;

  while (cin >> x){ // repeat while reading is successful
    cout << "input = " << x << endl;
    sum += x;       // add number to sum
  }
  cout << "sum = " << sum << endl;
}