import iotbx.pdb

def run():
  xrs = iotbx.pdb.input(file_name = "model.pdb").xray_structure_simple()
  xrs1 = xrs.expand_to_p1(sites_mod_positive=True)
  xrs2 = xrs.expand_to_p1(sites_mod_positive=False)
  print >> open("1.pdb","w"), xrs1.as_pdb_file()
  print >> open("2.pdb","w"), xrs2.as_pdb_file()
    
   
if (__name__ == "__main__"):
  run()