## main163

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    // main163.cc is a part of the PYTHIA event generator.
    // Copyright (C) 2026 Torbjorn Sjostrand.
    // PYTHIA is licenced under the GNU GPL v2 or later, see COPYING for details.
    // Please respect the MCnet Guidelines, see GUIDELINES for details.

    // Keywords:
    //            Matching
    //            Merging
    //            MLM

    // This is a sample program showing Alpgen- or Madgraph-style MLM matching
    // for Madgraph LHEF or native Alpgen format event files.
    //
    // Please see the 'Jet Matching Style' manual page for a description of the
    // parameters and user options.

    // Includes and namespace
    #include "Pythia8/Pythia.h"
    #include "Pythia8Plugins/CombineMatchingInput.h"
    using namespace Pythia8;

    //==========================================================================

    int main() {

     // Generator and read in commands.
      Pythia pythia;
      pythia.readFile("main163.cmnd");

      // Extract settings to be used in the main program.
      int nEvent = pythia.mode("Main:numberOfEvents");
      int nAbort = pythia.mode("Main:timesAllowErrors");
      int nSkip  = pythia.mode("Main:spareMode1");

      // Create UserHooks pointer. Stop if it failed. Pass pointer to Pythia.
      CombineMatchingInput combined;
      combined.setHook(pythia);

      // If Pythia fails to initialize, exit with error.
      if (!pythia.init()) return 1;

      // Optionally skip ahead in LHEF.
      pythia.LHAeventSkip( nSkip );

      // Begin event loop. Optionally quit it before end of file.
      int iAbort = 0;
      for (int iEvent = 0; ;  ++iEvent) {
        if (nEvent > 0 && iEvent >= nEvent) break;

        // Generate events. Quit if at end of file or many failures.
        if (!pythia.next()) {
          if (pythia.info.atEndOfFile()) {
            cout << "Info: end of input file reached" << endl;
            break;
          }
          if (++iAbort < nAbort) continue;
          cout << "Abort: too many errors in generation" << endl;
          break;
        }

        // Event analysis goes here.

      // End of event loop.
      }

      // Final statistics and done.
      pythia.stat();

      return 0;
    }