#include <iostream>
#include <boost/multiprecision/cpp_bin_float.hpp>


typedef boost::multiprecision::number<boost::multiprecision::backends::cpp_bin_float<128, boost::multiprecision::backends::digit_base_2> > ext_float_t;

int main(int, char**) {
  ext_float_t a = 1;
  ext_float_t b("3e-39"); // b > 2^-128
  ext_float_t c = a + b;
  std::cout
    << std::setprecision(45) 
    << a << " + " << b << " = " << c << "\n"
    ;
  if (c == a)
    std::cout << "bad\n";
  else
    std::cout << "good\n";
  
  return 0;
}