/********************** STEP 2 **********************/
  cout<<"Step 2: You now need to write also the oscillation function, with variable parameters."<<endl;
  cout<<"Go back to your exercise sheet and look for the oscillation probability function you just obtained."<<endl;
  cout<<"Starting from the oscillation probability function, try to write in root the survival probability function as a funcion of the antineutrino energy, x."<<endl;
  cout<<"The 3 parameters that you need are [0] = the distance (in km), [1] = the mixing, and [2] = the Dm^2"<<endl;
  cout<<"Write the function in 'TF1 *oscil' below. Hint: f(x)^n in root is pow(f(x),n)"<<endl<<endl<<endl;

  //Once completed the TF1 *oscil function comment the line below
  return;

  //Survival probability function - with parameters distance in km=[0],mixing=[1],Dm2=[2]
  TF1 *oscil=new TF1("oscil","---write-function-here---",0.,10.); 

  //Set and fix the oscillation parameters [1] and [2]
  oscil->SetParameter(1,0.856); oscil->FixParameter(1,0.856);
  oscil->SetParameter(2,8.e-5); oscil->FixParameter(2,8.e-5);
 
  cout<<"Then you need to enter also the relevant distance for the Far Detector."<<endl<<endl<<endl;

  //Once dFar has been set, comment the line below
  return;

  //Far detector
  //Set the distance for the far detector in km
  double dFar;//= ---write-value-here---; //km -- set here the distance of the far detector
  oscil->SetParameter(0,dFar);

  oscil->SetNpx(300);
  oscil->Draw(); 
  return;
  //comment '//' the two lines above and paste STEP 3 to proceed with the exercise