#include <iostream>
#include <cmath>
using namespace std;

int main() {
  double a = 0.1;
  double eighth_root = sqrt(sqrt(sqrt(a)));
  double b = pow(eighth_root, 8.0);
  // uncomment the following line and it will _look_ like b is 0.1,
  //   but in fact that is because of internal rounding
  //cout << "a = " << a << ", 8th root of a to the 8th power: " << b << endl;
  if ( a + b == 0.2 )
    cout << "Yes, arithmetic works." << endl;
  else
    cout << "0.1 + 0.1 is NOT 0.2 in doubles." << endl;
  return 0;
}