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:
/*
 * Remember a 6.0 student can know more than a 10.0 student.
 * Grades don't determine intelligence, they test obedience. 
 * I Never Give Up.
 * I will become Candidate Master.
 * I will defeat Saurabh Anand.
 * Skills are Cheap,Passion is Priceless.
 */
import java.util.*;
import java.util.Map.Entry;
import java.io.*;
import java.text.*;

import static java.lang.System.out;
import static java.util.Arrays.*;
import static java.lang.Math.*;
public class ContestMain {
	private static Reader in=new Reader();
	private static StringBuilder ans=new StringBuilder();
	private static long MOD=1000000000+7;//10^9+7
	private static final int N=100000+7; //10^5+7
//	private static final double EPS=1e-9;
//	private static final int LIM=26;
//	private static final double PI=3.1415;
	private static ArrayList<Integer> v[]=new ArrayList[N];
//	private static int color[]=new int[N];
	private static boolean mark[]=new boolean[N];
//	private static BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
//	private static ArrayList<Pair> v[]=new ArrayList[N];
	private static long powmod(long x,long n){
		if(n==0||x==0)return 1;
		else if(n%2==0)return(powmod((x*x)%MOD,n/2));
		else return (x*(powmod((x*x)%MOD,(n-1)/2)))%MOD;
	}
//	private static void shuffle(long [] arr) {
//		for (int i = arr.length - 1; i >= 2; i--) {
//			int x = new Random().nextInt(i - 1);
//	        long temp = arr[x];
//	        arr[x] = arr[i];
//	        arr[i] = temp;
//	    }
//	 }
//	private static long gcd(long a, long b){
//		if(b==0)return a;
//		return gcd(b,a%b);
//	}
//	private static boolean check(int x,int y){
//		if((x>=0&&x<n)&&(y>=0&&y<m)&&mat[x][y]!='X'&&!visited[x][y])return true;
//		return false;
//	}
//	static class Node{
//		int left;
//		int right;
//		Node(){
//			left=0;
//			right=0;
//		}
//	}
	static HashSet<Integer> seta=new HashSet();
	static HashSet<Integer> setb=new HashSet();
	static boolean flag=true;
	public static void dfs(int node,int c){
		mark[node]=true;
		if(c==0)seta.add(node);
		else setb.add(node);
		for(int x:v[node]){
			if(!mark[x]){
				if(c==0)dfs(x,1);
				else dfs(x,0);
			}
			else {
				if((c==0&&seta.contains(x))||(c==1&&setb.contains(x))){
					flag=false;
					return;
				}
			}
		}
	}
	public static void main(String[] args) throws IOException{
		int n=in.nextInt();
		int m=in.nextInt();
		for(int i=0;i<=n;i++)
			v[i]=new ArrayList();
		int x,y;
		for(int i=0;i<m;i++){
			x=in.nextInt();
			y=in.nextInt();
			v[x].add(y);
			v[y].add(x);
		}
		for(int i=0;i<=n;i++){
			if(v[i].size()!=0&&!mark[i]){
				dfs(i,0);
			}
		}
		if(!flag)out.println(-1);
		else{
			out.println(seta.size());
			for(int a:seta){
				out.print(a+" ");
			}
			out.println();
			out.println(setb.size());
			for(int a:setb){
				out.print(a+" ");
			}
		}
	}
	static class Pair<T> implements Comparable<Pair>{
		int l;
		int r;
		Pair(){
			l=0;
			r=0;
		}
		Pair(int k,int v){
			l=k;
			r=v;
		}
		@Override
		public int compareTo(Pair o) {
			if(o.l!=l)return (int) (l-o.l);
			else return (int)(r-o.r);
		}
		
	}
	static class Reader{
        BufferedReader br;
        StringTokenizer st;
        public Reader()
        {
            br = new BufferedReader(new
                     InputStreamReader(System.in));
        }
 
        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
     
                	st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt()
        {
            return Integer.parseInt(next());
        }
 
        long nextLong()
        {
            return Long.parseLong(next());
        }
 
        double nextDouble()
        {
            return Double.parseDouble(next());
        }
 
        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
}