
import os
from argparse import ArgumentParser
from pathlib import Path
from shutil import copyfile, rmtree
from typing import Generator

import datasets.config
from datasets.builder import DatasetBuilder
from datasets.commands import BaseDatasetsCLICommand
from datasets.download.download_manager import DownloadMode
from datasets.load import dataset_module_factory, import_main_class
from datasets.utils.filelock import logger as fl_logger
from datasets.utils.info_utils import VerificationMode
from datasets.utils.logging import ERROR, get_logger


UpperCAmelCase__						:	Tuple	     = get_logger(__name__)






def     lowerCamelCase__				(   a ) ->  str:
   return TestCommand(
       args.dataset						,						args.name						,						args.cache_dir						,						args.data_dir						,						args.all_configs						,						args.save_info or args.save_infos						,						args.ignore_verifications						,						args.force_redownload						,						args.clear_cache						,						)






class UpperCAmelCase  (		SCREAMING_SNAKE_CASE__  ):





   '''simple docstring'''
   __UpperCamelCase						:       Optional[int]												=       False  # to tell pytest it's not a test class


   @staticmethod
   def 					__magic_name__							(   lowerCAmelCase_	:				ArgumentParser	):

      """simple docstring"""
      _A:    List[str]						     =			parser.add_parser('''test'''     ,     help='''Test dataset implementation.'''	)
      test_parser.add_argument('''--name'''     ,     type=lowerCAmelCase_     ,     default=lowerCAmelCase_     ,     help='''Dataset processing name'''	)
      test_parser.add_argument(
          '''--cache_dir'''     ,     type=lowerCAmelCase_     ,     default=lowerCAmelCase_     ,     help='''Cache directory where the datasets are stored.'''     ,     )
      test_parser.add_argument(
          '''--data_dir'''     ,     type=lowerCAmelCase_     ,     default=lowerCAmelCase_     ,     help='''Can be used to specify a manual directory to get the files from.'''     ,     )
      test_parser.add_argument('''--all_configs'''     ,     action='''store_true'''     ,     help='''Test all dataset configurations'''	)
      test_parser.add_argument(
          '''--save_info'''     ,     action='''store_true'''     ,     help='''Save the dataset infos in the dataset card (README.md)'''	)
      test_parser.add_argument(
          '''--ignore_verifications'''     ,     action='''store_true'''     ,     help='''Run the test without checksums and splits checks.'''     ,     )
      test_parser.add_argument('''--force_redownload'''     ,     action='''store_true'''     ,     help='''Force dataset redownload'''	)
      test_parser.add_argument(
          '''--clear_cache'''     ,     action='''store_true'''     ,     help='''Remove downloaded files and cached datasets after each config test'''     ,     )
      # aliases
      test_parser.add_argument('''--save_infos'''     ,     action='''store_true'''     ,     help='''alias to save_info'''	)
      test_parser.add_argument('''dataset'''     ,     type=lowerCAmelCase_     ,     help='''Name of the dataset to download'''	)
      test_parser.set_defaults(func=_test_command_factory	)


   def __init__(   self	:				List[str]     ,     lowerCAmelCase_	:				str     ,     lowerCAmelCase_	:				str     ,     lowerCAmelCase_	:				str     ,     lowerCAmelCase_	:				str     ,     lowerCAmelCase_	:				bool     ,     lowerCAmelCase_	:				bool     ,     lowerCAmelCase_	:				bool     ,     lowerCAmelCase_	:				bool     ,     lowerCAmelCase_	:				bool     ,     ):

      """simple docstring"""
      _A:    Optional[Any]						     =			dataset
      _A:    Dict						     =			name
      _A:    Dict						     =			cache_dir
      _A:    Tuple						     =			data_dir
      _A:    str						     =			all_configs
      _A:    List[str]						     =			save_infos
      _A:    int						     =			ignore_verifications
      _A:    Optional[Any]						     =			force_redownload
      _A:    int						     =			clear_cache
      if clear_cache and not cache_dir:
         print(
             '''When --clear_cache is used, specifying a cache directory is mandatory.\n'''
             '''The \'download\' folder of the cache directory and the dataset builder cache will be deleted after each configuration test.\n'''
             '''Please provide a --cache_dir that will be used to test the dataset script.'''	)
         exit(1	)
      if save_infos:
         _A:    int						     =			True


   def 					__magic_name__							(   self	:				Optional[int]	):

      """simple docstring"""
      fl_logger().setLevel(lowerCAmelCase_	)
      if self._name is not None and self._all_configs:
         print('''Both parameters `config` and `all_configs` can\'t be used at once.'''	)
         exit(1	)
      _A     ,    _A:    Dict						     =			self._dataset, self._name
      _A:    str						     =			dataset_module_factory(lowerCAmelCase_	)
      _A:    Optional[int]						     =			import_main_class(module.module_path	)
      _A:    List[str]						     =			len(builder_cls.BUILDER_CONFIGS	) if self._all_configs and builder_cls.BUILDER_CONFIGS else 1

      def get_builders() -> Generator[DatasetBuilder, None, None]:
         if self._all_configs and builder_cls.BUILDER_CONFIGS:
            for i, config in enumerate(builder_cls.BUILDER_CONFIGS	):
               if "config_name" in module.builder_kwargs:
                  yield builder_cls(
                      cache_dir=self._cache_dir     ,     data_dir=self._data_dir     ,     **module.builder_kwargs     ,     )
               else:
                  yield builder_cls(
                      config_name=config.name     ,     cache_dir=self._cache_dir     ,     data_dir=self._data_dir     ,     **module.builder_kwargs     ,     )
         else:
            if "config_name" in module.builder_kwargs:
               yield builder_cls(cache_dir=self._cache_dir     ,     data_dir=self._data_dir     ,     **module.builder_kwargs	)
            else:
               yield builder_cls(
                   config_name=lowerCAmelCase_     ,     cache_dir=self._cache_dir     ,     data_dir=self._data_dir     ,     **module.builder_kwargs     ,     )

      for j, builder in enumerate(get_builders()	):
         print(F"""Testing builder '{builder.config.name}' ({j + 1}/{n_builders})"""	)
         _A:    Optional[int]						     =			os.path.exists(
             os.path.join(builder.get_imported_module_dir()     ,     datasets.config.DATASETDICT_INFOS_FILENAME	)	)  # record checksums only if we need to update a (deprecated) dataset_infos.json
         builder.download_and_prepare(
             download_mode=DownloadMode.REUSE_CACHE_IF_EXISTS
             if not self._force_redownload
             else DownloadMode.FORCE_REDOWNLOAD     ,     verification_mode=VerificationMode.NO_CHECKS
             if self._ignore_verifications
             else VerificationMode.ALL_CHECKS     ,     try_from_hf_gcs=lowerCAmelCase_     ,     )
         builder.as_dataset()
         if self._save_infos:
            builder._save_infos()

         # If save_infos=True, the dataset card (README.md) is created next to the loaded module file.
         # The dataset_infos are saved in the YAML part of the README.md

         # Let's move it to the original directory of the dataset script, to allow the user to
         # upload them on S3 at the same time afterwards.
         if self._save_infos:
            _A:    Tuple						     =			os.path.join(builder_cls.get_imported_module_dir()     ,     '''README.md'''	)
            _A:    List[Any]						     =			Path(lowerCAmelCase_	).name + '''.py'''
            _A:    Optional[Any]						     =			os.path.join(lowerCAmelCase_     ,     lowerCAmelCase_	)
            if os.path.isfile(lowerCAmelCase_	):
               _A:    Optional[Any]						     =			os.path.dirname(lowerCAmelCase_	)
            elif os.path.isfile(lowerCAmelCase_	):
               _A:    Dict						     =			path
            elif os.path.isdir(lowerCAmelCase_	):  # for local directories containing only data files
               _A:    Optional[int]						     =			path
            else:  # in case of a remote dataset
               _A:    str						     =			None
               print(F"""Dataset card saved at {dataset_readme_path}"""	)

            # Move dataset_info back to the user
            if dataset_dir is not None:
               _A:    Union[str, Any]						     =			os.path.join(lowerCAmelCase_     ,     '''README.md'''	)
               copyfile(lowerCAmelCase_     ,     lowerCAmelCase_	)
               print(F"""Dataset card saved at {user_dataset_readme_path}"""	)

            # If clear_cache=True, the download folder and the dataset builder cache directory are deleted
         if self._clear_cache:
            if os.path.isdir(builder._cache_dir	):
               logger.warning(F"""Clearing cache at {builder._cache_dir}"""	)
               rmtree(builder._cache_dir	)
            _A:    Optional[int]						     =			os.path.join(self._cache_dir     ,     datasets.config.DOWNLOADED_DATASETS_DIR	)
            if os.path.isdir(lowerCAmelCase_	):
               logger.warning(F"""Clearing cache at {download_dir}"""	)
               rmtree(lowerCAmelCase_	)

      print('''Test successful.'''	)





from __future__ import annotations






def     lowerCamelCase__				(   a ) ->  Union[str, Any]:
   global graph, reversed_graph, scc, component, visit, stack
   if visit[u]:
      return
   _A:    Optional[Any]						     =			True
   for v in graph[u]:
      dfs(a )
   stack.append(a )






def     lowerCamelCase__				(   a ) ->  List[Any]:
   global graph, reversed_graph, scc, component, visit, stack
   if visit[u]:
      return
   _A:    str						     =			True
   component.append(a )
   for v in reversed_graph[u]:
      dfsa(a )






def     lowerCamelCase__				(   ) ->  str:
   global graph, reversed_graph, scc, component, visit, stack
   for i in range(a ):
      dfs(a )
   _A:    Optional[Any]						     =			[False] * n
   for i in stack[::-1]:
      if visit[i]:
         continue
      _A:    Optional[Any]						     =			[]
      dfsa(a )
      scc.append(a )
   return scc


if __name__ == "__main__":
   # n - no of nodes, m - no of edges
   UpperCAmelCase__     ,UpperCAmelCase__						:	Any	     = list(map(int, input().strip().split()))

   UpperCAmelCase__						:	list[list[int]]	     = [[] for _ in range(n)]  # graph
   UpperCAmelCase__						:	list[list[int]]	     = [[] for i in range(n)]  # reversed graph
   # input graph data (edges)
   for _ in range(m):
      UpperCAmelCase__     ,UpperCAmelCase__						:	str	     = list(map(int, input().strip().split()))
      graph[u].append(v)
      reversed_graph[v].append(u)

   UpperCAmelCase__						:	list[int]	     = []
   UpperCAmelCase__						:	list[bool]	     = [False] * n
   UpperCAmelCase__						:	list[int]	     = []
   UpperCAmelCase__						:	list[int]	     = []
   print(kosaraju())



