{
    TFile *myfile = new TFile("myfile.root");
    
    int eventno;
    int version;
    int npoints;
    double px[100],py[100],pz[100];
    bool isgood[100];
    
    TTree *mytree;
    myfile->GetObject("mytree",mytree);
    
    mytree->SetBranchAddress("eventno",&eventno);
    mytree->SetBranchAddress("version",&version);
    mytree->SetBranchAddress("npoints",&npoints);
    mytree->SetBranchAddress("px",px);
    mytree->SetBranchAddress("py",py);
    mytree->SetBranchAddress("pz",pz);
    mytree->SetBranchAddress("isgood",isgood);
    
    int count = 0;
    for(int evt=0;evt<mytree->GetEntries();evt++) {
        mytree->GetEntry(evt);
        
        int count_pts = 0;
        for(int i=0;i<npoints;i++)
            if (isgood[i]) count_pts++;
        if (count_pts>10) count++;
    }
    
    printf("count = %d\n",count);
}