text: #!/usr/bin/python3
  # -*- coding: utf-8 -*-
  
  import os
  
  program = 'prob_f.py'
  testdir = 'icpc2018data/F-gowithflow/'
  files = os.listdir(testdir)
  
  for f in files:
      if f[-3:] == '.in':
          print('testing', f)
          os.system('python3 '+program+' < '+testdir+f+'>xxx')
          os.system('diff xxx '+testdir+f[:-2]+'ans')
  