import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.LinkedList;
import java.util.List;
import java.util.Stack;


public class Main {
	Node[] graph;
	int nodesCount;
	int edgesCount;
	int source;
	int[] distance;
	Color[] color;
	int[] parent;
	Stack<Integer> topSort = new Stack<Integer>();
	int time = 0;
	
	public static enum Color {
		WHITE,GREY,BLACK;
	}

	public class Node {
		int a, b;
		int discTime = 0;
		int finTime = 0;
		List<Integer> neighbors = new LinkedList<Integer>();

		
		public Node(int a, int b) {
			this.a = a;
			this.b = b;
		}
		
		public void addNeighbor(int u) {
			this.neighbors.add(u);
		}
		
		public List<Integer> getNeighbors() {
			return neighbors;
		}
	}
	
	public void init() {
		
		for (int u = 0; u < nodesCount; u++) {
			parent[u] = -1;
			color[u] = Color.WHITE;
		}
		
		for (int u = 0; u < nodesCount; u++) {
			if (color[u] == Color.WHITE) {
				dfs(u);
			}
		}
	}
	
	public void dfs(int u) {
	
		//graph[u].discTime = time++;
		color[u] = Color.GREY;
		for (int v : graph[u].getNeighbors()) {
			if (color[v] == Color.WHITE) {
				//parent[v] = u;
				dfs(v);
			}
		}
		//graph[u].finTime = time++;
		color[u] = Color.BLACK;
		topSort.add(u);
	}
	
	
	public void writeData() {
		PrintWriter out = null;
		try {
			out = new PrintWriter("sortaret.out");
			while (!topSort.isEmpty()) {
				int u = topSort.pop() + 1;
				out.write(u + " ");
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally {
			if (out != null ){ 
				out.close();
			}
		}

	}
	
	public void readData() {
		BufferedReader in;
		try {
			in = new BufferedReader(new FileReader("sortaret.in"));
			String line = in.readLine();
			String[] tokens = line.split(" ");

			nodesCount = Integer.valueOf(tokens[0]);
			edgesCount = Integer.valueOf(tokens[1]);
			
			graph = new Node[nodesCount];
			for (int i = 0; i < nodesCount; i++) {
				graph[i] = new Node(0, 0);
			}
			parent = new int[nodesCount];
			color = new Color[nodesCount];
			distance = new int[nodesCount];

			for (int i = 0; i < edgesCount; i++) {
				line = in.readLine();
				System.out.println(line);
				tokens = line.split(" ");
				int first = Integer.valueOf(tokens[0]) - 1;
				int second = Integer.valueOf(tokens[1]) - 1;
				graph[first].addNeighbor(second);
			}
			printGraph();
			
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	
	public void printGraph() {
		for (int u = 0; u < nodesCount; u++) {
			System.out.println(u);
			for (int v : graph[u].getNeighbors()) {
				System.out.print(v + " ");
			}
			System.out.println();
		}
	}

	public static void main(String[] args) {
		Main problem = new Main();
		problem.readData();
		problem.init();
		problem.writeData();

	}

}