namespace Sticks
{
    using System;
    using System.Collections.Generic;

    class Program
    {
        static void Main(string[] args)
        {
            int stickCount = int.Parse(Console.ReadLine());
            int stickPlacings = int.Parse(Console.ReadLine());

           Dictionary<int,List<int>> graph = new Dictionary<int, List<int>>();
            for (int i = 0; i < stickCount; i++)
            {
                graph[i] = new List<int>();
            }
            int[] predecessorsCount = new int[graph.Count];
            for (int i = 0; i < stickPlacings; i++)
            {
                var sticks = Console.ReadLine().Split(' ');
                var topStick = int.Parse(sticks[0]);
                var bottomStick = int.Parse(sticks[1]);
                graph[topStick].Add(bottomStick);
            }
            for (int stick = 0; stick < graph.Count; stick++)
            {
                foreach (int bottomStick in graph[stick])
                {
                    predecessorsCount[bottomStick]++;
                }
            }
            var isRemoved = new bool[graph.Count];
            var liftedSticks = new LinkedList<int>();
            var stickRemoved = true;
            while (stickRemoved)
            {
                stickRemoved = false;
                for (int stick = graph.Count - 1; stick >= 0; stick--)
                {
                    if (predecessorsCount[stick] == 0 && !isRemoved[stick])
                    {
                        foreach (int bottomStick in graph[stick])
                        {
                            predecessorsCount[bottomStick]--;
                        }
                        isRemoved[stick] = true;
                        stickRemoved = true;
                        liftedSticks.AddLast(stick);
                        break;
                    }
                }
            }
            if (liftedSticks.Count < graph.Count)
            {
                Console.WriteLine("Cannot lift all sticks");
            }

            Console.WriteLine(string.Join(" ",liftedSticks));
        }
    }
}