import java.io.*; import java.util.*; import java.util.stream.*; public class Main { static ArrayList> graph = new ArrayList<>(); static int[] values; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); int m = sc.nextInt(); values = new int[n]; Arrays.fill(values, -1); for (int i = 0; i < n; i++) { graph.add(new ArrayList<>()); } for (int i = 0; i < m; i++) { graph.get(sc.nextInt() - 1).add(sc.nextInt() - 1); } long ans = n; for (int i = 0; i < n; i++) { ans += check(i); } System.out.println(ans); } static int check(int x) { if (values[x] < 0) { values[x] = x; for (int y : graph.get(x)) { values[x] = Math.max(values[x], check(y)); } } return values[x]; } } class Utilities { static String arrayToLineString(Object[] arr) { return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n")); } static String arrayToLineString(int[] arr) { return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new)); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public int[] nextIntArray() throws Exception { return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray(); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }