float getExpRndmNumber(int max){
  //Implementation of the function.
  //Use a hit or miss aproach as in the previous excercise.
  return 1;
}

int ex12_frwl(){
  TH1F*  h1 = new TH1F("h1", "Exponentialverteilung", 100, 0, 10);
  const int iterations = 10000;

  for (int ii = 0; ii < iterations; ii++){
    h1->Fill(getExpRndmNumber(10));
  }

  h1->Draw();

  TF1* myExp = new TF1("myExp", "[0]*TMath::Exp(-x)", 0,10);

  //Parameter 0 needs to be set to a different value.
  //How do you calculate the right parameter value?
  myExp->SetParameter(0, 5); 
  myExp->Draw("same");
}