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

#include <gsl/gsl_sf_hyperg.h>


int
main (void)
{
  double x = 0.1725;
  double a = -10.34;
  double b = 2.05;
  double c = 3.05;

  double y = gsl_sf_hyperg_2F1(a,b,c,x);

  cout << "= " 
       << setprecision(18) << setw(20) << y << endl;

  return 0;
}