void script(){
TFile* f = TFile::Open("isotopes.root");
THStack *hs = new THStack("hs","Stacked 1D histograms");
hist->SetFillColor(kRed);
hs->Add(hist);
hist2->SetFillColor(kBlue);
hs->Add(hist2);
hs->Draw("hist");
TCanvas* c2 = new TCanvas();
hs->Draw("BAR1 TEXT0");
}