


'''simple docstring'''

# tests directory-specific settings - this file is run automatically
# by pytest before any tests are run

import sys
import warnings
from os.path import abspath, dirname, join


# allow having multiple repository checkouts and not needing to remember to rerun
# 'pip install -e .[dev]' when switching between checkouts and running tests.
__lowercase:		Optional[int]    						=  abspath(join(dirname(dirname(dirname(__file__))), "src"))
sys.path.insert(1, git_repo_path)


# silence FutureWarning warnings in tests since often we can't act on them until
# they become normal warnings - i.e. the tests still need to test the current functionality
warnings.simplefilter(action="ignore", category=FutureWarning)



def 							SCREAMING_SNAKE_CASE__(		_UpperCamelCase   :					int )		->       Dict:





   '''simple docstring'''







   from transformers.testing_utils import pytest_addoption_shared

   pytest_addoption_shared(_UpperCamelCase )






def 							SCREAMING_SNAKE_CASE__(		_UpperCamelCase   :					Optional[Any] )		->       Any:





   '''simple docstring'''







   from transformers.testing_utils import pytest_terminal_summary_main

   UpperCamelCase__			    =    terminalreporter.config.getoption("--make-reports" )
   if make_reports:
      pytest_terminal_summary_main(_UpperCamelCase     ,		id=_UpperCamelCase )

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())



