# include <cstdlib>
# include <iostream>
# include <iomanip>

using namespace std;

int main ( ) 
//
//  ADD_SMALL allows us to specify an increment Y to be added 
//  to the value X = 1.23456789. 
//
//  Since a float only has about 8 digits of accuracy, we will get
//  the answers we expect when Y = 1, 0.1, 0.01, 0.001, but as Y
//  decreases, the answers will start to look bad.  And when Y gets
//  very small, it can't be added to X at all.
//
{
  float x;
  float y;
  float z;

  x = 1.23456789;
  cout << "ADD_SMALL:\n";
  cout << "  Enter small Y to add to X = 1.23456789.\n";

  cin >> y;

  z = x + y;

  cout << "\n";
  cout << setprecision(12) << x << " + " << y << " = " << z << "\n";

  return 0;
}