1 HMERGE
  Syntax: HMERGE filout filein1 [filein2 [filein3 ...]]
   where: fileout  is the name of the output file
          filein1  is the first filename etc.

  Merges one or more HBOOK RZ files into a single output file. This
  command calls the HBOOK routine `HMERGE' which combines Ntuples and
  adds histograms. The files should have identical structures.
  A `<CR>' signifies that the list of files to merge has finished.

  A maximum of 100 files can be merged in one command.

