Problem: Recently, Pari and Arya did some research about NP-Hard problems and they found the minimum vertex cover problem very interesting.

Suppose the graph G is given. Subset A of its vertices is called a vertex cover of this graph, if for each edge uv there is at least one endpoint of it in this set, i.e. <image> or <image> (or both).

Pari and Arya have won a great undirected graph as an award in a team contest. Now they have to split it in two parts, but both of them want their parts of the graph to be a vertex cover.

They have agreed to give you their graph and you need to find two disjoint subsets of its vertices A and B, such that both A and B are vertex cover or claim it's impossible. Each vertex should be given to no more than one of the friends (or you can even keep it for yourself).

Input

The first line of the input contains two integers n and m (2 ≤ n ≤ 100 000, 1 ≤ m ≤ 100 000) — the number of vertices and the number of edges in the prize graph, respectively.

Each of the next m lines contains a pair of integers ui and vi (1 ≤ ui, vi ≤ n), denoting an undirected edge between ui and vi. It's guaranteed the graph won't contain any self-loops or multiple edges.

Output

If it's impossible to split the graph between Pari and Arya as they expect, print "-1" (without quotes).

If there are two disjoint sets of vertices, such that both sets are vertex cover, print their descriptions. Each description must contain two lines. The first line contains a single integer k denoting the number of vertices in that vertex cover, and the second line contains k integers — the indices of vertices. Note that because of m ≥ 1, vertex cover cannot be empty.

Examples

Input

4 2
1 2
2 3


Output

1
2 
2
1 3 


Input

3 3
1 2
2 3
1 3


Output

-1

Note

In the first sample, you can give the vertex number 2 to Arya and vertices numbered 1 and 3 to Pari and keep vertex number 4 for yourself (or give it someone, if you wish).

In the second sample, there is no way to satisfy both Pari and Arya.

Solution (in JAVA):

Solution:
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
import java.util.StringTokenizer;

public class nphardproblem {
	public static Scanner sc = new Scanner(System.in);
	public static StringTokenizer st;
	public static PrintWriter pw = new PrintWriter(System.out);
	final static boolean debugmode = true;
	public static int k = 7; // for 10^9 + k mods.
	public static long STMOD = 1000000000 + k; // 10^9 + k
	public static void main(String[] args) {
		int n = getInt();
		int m = getInt();
		HashSet<Integer> traversed = new HashSet<Integer>();

		NodeQQ[] graph = new NodeQQ[n];
		for(int i = 0;i<n;i++){graph[i]  = new NodeQQ();traversed.add(i);}
		for(int i = 0;i<m;i++){
			int start = getInt()-1;
			int end = getInt()-1;
			graph[start].addEdge(end);
			graph[end].addEdge(start);
		}
		
		LinkedList<Integer> negset = new LinkedList<Integer>();
		LinkedList<Integer> posset = new LinkedList<Integer>();
		for(int unhit = 0;unhit<n;unhit++){
			if(traversed.contains(unhit) && graph[unhit].children.size() > 0){
				Queue<Integer> q = new LinkedList<Integer>();
				graph[unhit].color = 1;
				posset.add(unhit);
				q.add(unhit);
				traversed.remove(unhit);
				while(q.size() != 0){
					int last = q.remove();
					int nn = -1*graph[last].color;
					
					for(int targets : graph[last].children){
						if(graph[targets].color == 0){
							graph[targets].color = nn;
							if(nn == -1){
								negset.add(targets);
							}
							else{
								posset.add(targets);
							}
							q.add(targets);
							traversed.remove(targets);
						}
						else if(graph[targets].color != nn){
							System.out.println(-1);
							return;
						}
					}
				}
			}
		}
		System.out.println(negset.size());
		for(int i : negset){
			System.out.print((i+1)+" ");
		}
		System.out.println("");
		System.out.println(posset.size());
		for(int i : posset){
			System.out.print((i+1)+" ");
		}
		
	}
	public static void debug(String toPrint){
		if(!debugmode) {return;}
		pw.println("[DEBUG]: "+toPrint);
	}
	public static void  submit(int[] k){
		pw.println(Arrays.toString(k));
		pw.close();
	}
	public static void submit(int p){
		pw.println(Integer.toString(p));
		pw.close();
	}
	public static void submit(String k){
		pw.println(k);
		pw.close();
	}
	public static void submit(double u){
		pw.println(Double.toString(u));
		pw.close();
	}
	public static void submit(long lng){
		pw.println(Long.toString(lng));
		pw.close();
		
	}
	public static int getInt(){
		if (st != null && st.hasMoreTokens()){
			return Integer.parseInt(st.nextToken());
		}
		st = new StringTokenizer(sc.nextLine());
		return Integer.parseInt(st.nextToken());
	}
	public static long getLong(){
		if (st != null && st.hasMoreTokens()){
			return Long.parseLong(st.nextToken());
		}
		st = new StringTokenizer(sc.nextLine());
		return Long.parseLong(st.nextToken());
	}
	public static double getDouble(){
		if (st != null && st.hasMoreTokens()){
			return Double.parseDouble(st.nextToken());
		}
		st = new StringTokenizer(sc.nextLine());
		return Double.parseDouble(st.nextToken());
	}
	public static String getString(){
		if(st != null && st.hasMoreTokens()){
			return st.nextToken();
		}
		st = new StringTokenizer(sc.nextLine());
		return st.nextToken();
	}
	public static String getLine(){
		return sc.nextLine();
	}
	public static int[][] readMatrix(int lines,int cols){
		int[][] matrr = new int[lines][cols];
		for (int i = 0;i < lines;i++){
			for(int j = 0;j < cols;j++){
				matrr[i][j] = getInt();
			}
		}
		return matrr;
	}
	public static int[] readArray(int lines){
		int[] ar = new int[lines];		
		for (int i = 0;i<lines;i++) ar[i] =getInt();
		return ar;
	}
}
class NodeQQ{
	public int color;
	public ArrayList<Integer> children;
	public NodeQQ(){
		children = new ArrayList<Integer>();	
		color = 0;
	}
	public void addEdge(int target){
		children.add(target);
	}
}