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

public class SticksTopologicalSorting {

    public static void main(String[] args) throws IOException {
        BufferedReader buffReader = new BufferedReader(new InputStreamReader(System.in));
        int stickCount = Integer.valueOf(buffReader.readLine());
        int stickPlacings = Integer.valueOf(buffReader.readLine());

        HashMap<Integer, List<Integer>> graph = new HashMap<>();
        for (int i = 0; i < stickCount; i++) {
            graph.put(i, new LinkedList<>());
        }
        int[] predecessorsCount = new int[graph.size()];
        for (int i = 0; i < stickPlacings; i++) {
            String[] sticks = buffReader.readLine().split("\\s+");
            int topStick = Integer.valueOf(sticks[0]);
            int bottomStick = Integer.valueOf(sticks[1]);
            graph.get(topStick).add(bottomStick);
        }
        for (int stick = 0; stick < graph.size(); stick++) {
            for (int bottomStick : graph.get(stick)) {
                predecessorsCount[bottomStick]++;
            }
        }
        boolean[] isRemoved = new boolean[graph.size()];
        Queue<Integer> liftedSticks = new LinkedList<>();
        boolean stickRemoved = true;
        while (stickRemoved) {
            stickRemoved = false;
            for (int stick = graph.size() - 1; stick >= 0; stick--) {
                if (predecessorsCount[stick] == 0 && !isRemoved[stick]) {
                    for (int bottomStick : graph.get(stick)) {
                        predecessorsCount[bottomStick]--;
                    }
                    isRemoved[stick] = true;
                    stickRemoved = true;
                    liftedSticks.add(stick);
                    break;
                }
            }
        }
        if (liftedSticks.size() < graph.size()) {
            System.out.println("Cannot lift all sticks");
        }

        while (!liftedSticks.isEmpty()) {
            System.out.print(liftedSticks.poll() + " ");
        }
    }
}