{

    

    PReaction my_reaction("3.5", "p", "p", "p p rho0");
    TH1F *histo1 = new TH1F ("histo1", "dilepton mass", 100, 0.2, 1.3);
    histo1->Sumw2();
    histo1->SetMinimum(0.000000001);
    my_reaction.Do(histo1, "_x =  ([rho0])->M()");

    my_reaction.Print();   //The "Print()" statement is optional
    my_reaction.Loop(10000);
    histo1->Draw("e1");
    
    PReaction my_reaction2("3.5", "p", "p","p p rho0 [e+ e-]");
    TH1F *histo2 = new TH1F ("histo2", "dilepton mass", 100, 0.2, 1.3);
    histo2->Sumw2();
    my_reaction2.Do(histo2, "_x =  ([rho0])->M()");

    my_reaction2.Print();   //The "Print()" statement is optional
    my_reaction2.Loop(10000);
    histo2->Draw("samee1");


}