
'''simple docstring'''





from itertools import combinations, product





def     snake_case							(						UpperCAmelCase ,					UpperCAmelCase ,					UpperCAmelCase ,					UpperCAmelCase		)->     Tuple:







						"""simple docstring"""
						if xa == ya == 0 or xa == ya == 0:
												return False
						__A    		=     xa * xa + ya * ya
						__A    		=     xa * xa + ya * ya
						__A    		=     (xa - xa) * (xa - xa) + (ya - ya) * (ya - ya)
						return (
						    a_square + b_square == c_square
						    or a_square + c_square == b_square
						    or b_square + c_square == a_square
						)





def     snake_case							(						UpperCAmelCase = 5_0		)->     List[str]:







						"""simple docstring"""
						return sum(
						    1
						    for pta, pta in combinations(product(range(limit + 1		) ,					repeat=2		) ,					2		)
						    if is_right(*lowerCamelCase_ ,					*lowerCamelCase_		)		)


if __name__ == "__main__":
	print(f'''{solution() = }''')








'''simple docstring'''





from __future__ import annotations





def     snake_case							(						UpperCAmelCase		)->     List[Any]:







      """simple docstring"""
      global graph, reversed_graph, scc, component, visit, stack
      if visit[u]:
            return
      __A    		=     True
      for v in graph[u]:
            dfs(UpperCAmelCase		)
      stack.append(UpperCAmelCase		)





def     snake_case							(						UpperCAmelCase		)->     List[Any]:







      """simple docstring"""
      global graph, reversed_graph, scc, component, visit, stack
      if visit[u]:
            return
      __A    		=     True
      component.append(UpperCAmelCase		)
      for v in reversed_graph[u]:
            dfsa(UpperCAmelCase		)





def     snake_case							(						)->     Any:







      """simple docstring"""
      global graph, reversed_graph, scc, component, visit, stack
      for i in range(UpperCAmelCase		):
            dfs(UpperCAmelCase		)
      __A    		=     [False] * n
      for i in stack[::-1]:
            if visit[i]:
                  continue
            __A    		=     []
            dfsa(UpperCAmelCase		)
            scc.append(UpperCAmelCase		)
      return scc


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

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

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






