import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class SticksTopologicalSorting {

    static boolean[] visited;
    static HashMap<Integer, List<Integer>> stickMap = new HashMap<>();
    static LinkedList<Integer> results = new LinkedList<>();
    static HashSet<Integer> currentVisited = new HashSet<>();
    static boolean[] hasOnTop;

    public static void main(String[] args) throws IOException {

        BufferedReader buffReader = new BufferedReader(new InputStreamReader(System.in));
        int sticks = Integer.parseInt(buffReader.readLine());
        int placings = Integer.parseInt(buffReader.readLine());
        visited = new boolean[sticks];
        hasOnTop = new boolean[sticks];
        for (int i = 0; i < sticks; i++) {
            stickMap.put(i, new LinkedList<>());
        }
        for (int i = 0; i < placings; i++) {
            String[] params = buffReader.readLine().split(" ");
            int parent = Integer.parseInt(params[0]);
            int child = Integer.parseInt(params[1]);
            stickMap.get(parent).add(child);
            hasOnTop[child] = true;
        }
        List<Integer> start = new LinkedList<>();
        for (int i = 0; i < sticks; i++) {
            if (!hasOnTop[i]) {
                start.add(i);
            }
        }

        for (int num : start) {
            try {
                topSortDfs(num, num);
            } catch (IllegalArgumentException ex) {

            }
        }
        if (results.size() < sticks) {
            System.out.println("Cannot lift all sticks");
        }
        for (int liftedStick : results) {
            System.out.print(liftedStick + " ");
        }
    }

    private static void topSortDfs(int starter, int vertex) {
        if (currentVisited.contains(vertex)) {
            results.addFirst(starter);
            throw new IllegalArgumentException();
        }
        if (!visited[vertex]) {
            currentVisited.add(vertex);
            visited[vertex] = true;
            List<Integer> children = stickMap.get(vertex);

            for (int child : children) {
                topSortDfs(starter, child);
            }
            results.addFirst(vertex);

            currentVisited.remove(vertex);
        }
    }
}