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.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.math.BigInteger;
import java.security.interfaces.DSAKey;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;
import java.util.Stack;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;

public class a {

	public static class in {
		static BufferedReader reader;
		static StringTokenizer tokenizer;

		static void init(InputStream input) throws FileNotFoundException {
			// reader = new BufferedReader(new
			// FileReader("B-small-attempt4.in"));
			reader = new BufferedReader(new InputStreamReader(input));
			tokenizer = new StringTokenizer("");
		}

		static String next() throws IOException {
			while (!tokenizer.hasMoreTokens())
				tokenizer = new StringTokenizer(reader.readLine());
			return tokenizer.nextToken();
		}

		static int nextInt() throws IOException {
			return Integer.parseInt(next());
		}

		static double nextDouble() throws IOException {
			return Double.parseDouble(next());
		}

		static long nextLong() throws IOException {
			return Long.parseLong(next());
		}
	}

	public static long comp(int n, int r) {
		r = Math.min(r, n - r);
		long ans = 1;
		for (int i = 1; i <= r; i++) {
			ans = ans * (long) (n - r + i) / (long) i;
		}
		return ans;

	}

	public static class node {

		int st;
		int end;
		int p;

		node(int st, int end, int p) {
			this.st = st;
			this.end = end;
			this.p = p;

		}

	}

	public static int gcd(int x, int y) {
		if (y == 0)
			return x;
		return gcd(y, x % y);
	}

	public static int tree[];

	public static void add(int idx, long val, int n, int tree[]) {

		while (idx <= n) {
			tree[idx] += val;
			idx += (idx & -idx);
		}
	}

	public static int get(int idx) {
		int g = 0;
		while (idx > 0) {

			g += tree[idx];
			idx -= (idx & -idx);
		}

		return g;
	}

	public static class point implements Comparable<point> {
		int min;
		int a;
		int b;

		point(int min, int a, int b) {
			this.min = min;
			this.a = a;
			this.b = b;
		}

		@Override
		public int compareTo(point o) {
			if (o.min > min)
				return 1;
			else if (o.min < min)
				return -1;
			return 0;
		}
	}

	// for bad input
	static String ReadLn(int maxLg) {
		byte lin[] = new byte[maxLg];
		int lg = 0, car = -1;
		String line = "";

		try {
			while (lg < maxLg) {
				car = System.in.read();
				if ((car < 0) || (car == '\n'))
					break;
				lin[lg++] += car;
			}
		} catch (IOException e) {
			return (null);
		}

		if ((car < 0) && (lg == 0))
			return (null);
		return (new String(lin, 0, lg));
	}

	// IMPORT LIBRARY PACKAGES NEEDED BY YOUR PROGRAM
	// SOME CLASSES WITHIN A PACKAGE MAY BE RESTRICTED
	// DEFINE ANY CLASS AND METHOD NEEDED
	// LNode CLASS IS DEFINED BY DEFAULT
	// CLASS BEGINS, THIS CLASS IS REQUIRED

	public class LNode {
		public int value;
		public LNode next;

	}

	public static class ReverseLinkedList {
		// METHOD SIGNATURE BEGINS, THIS METHOD IS REQUIRED
		public static LNode reverseLinkedList(LNode list) {
			// INSERT YOUR CODE HERE
			int n = 0;
			LNode pointer = list;
			while (pointer != null) {
				n++;
				pointer = pointer.next;
			}

			int mid = (n + 1) / 2;
			if (n % 2 == 1)
				mid--;
			LNode arr[] = new LNode[n - mid];
			pointer = list;
			int p = 0;
			int c = 0;
			while (pointer != null) {

				if (c >= mid) {
					arr[p++] = pointer;
				}
				c++;
				pointer = pointer.next;
			}
			LNode swap = null;
			for (int i = 0; i < (n - mid) / 2; i++) {
				swap = arr[i];
				arr[i] = arr[n - mid - 1 - i];
				arr[n - mid - 1 - i] = swap;
			}

			pointer = list;
			p = 0;
			c = 0;
			while (pointer != null) {

				if (c >= mid - 1) {
					pointer.next = arr[p++];
				}
				c++;
				pointer = pointer.next;
			}

			return list;
		}
		// METHOD SIGNATURE ENDS
	}

	public static class points implements Comparable<points> {

		int dur;
		int idx;

		points(int d, int i) {
			dur = d;
			idx = i;
		}

		@Override
		public int compareTo(points o) {
			if (o.dur < dur)
				return 1;
			else if (o.dur > dur)
				return -1;
			else if (o.idx < idx)
				return 1;
			else
				return -1;

		}
	}

	public static ArrayList<Integer> prime;

	public static void prime(int x) {
		prime = new ArrayList();
		boolean vis[] = new boolean[x + 1];
		for (int i = 2; i * i <= x; i++) {
			if (!vis[i]) {
				for (long j = (long) i * (long) i; j <= x; j += i) {
					vis[(int) j] = true;
				}
			}
		}
		int c = 0;
		for (int i = 2; i <= x; i++) {
			if (!vis[i]) {
				prime.add(i);
				c++;
			}

		}
	}

	public static int dp[];

	public static void solve(int a[], int k) {
		dp = new int[k + 1];
		dp[0] = 1;

		for (int i = 0; i < a.length; i++) {
			for (int j = k - a[i]; j >= 0; j--) {
				dp[j] += dp[i];
			}
		}
	}

	public static ArrayList<Integer> graph[];
	public static HashSet<Integer> first;
	public static HashSet<Integer> second;
	public static boolean vis[];

	public static void solve(int node, int bol) {
		if (bol == 0)
			first.add(node);
		else
			second.add(node);
		vis[node] = true;
		for (int i = 0; i < graph[node].size(); i++) {
			if (vis[graph[node].get(i)])
				continue;
			solve(graph[node].get(i), 1 - bol);
		}
	}

	public static void main(String[] args) throws IOException {
		// StringBuilder qq = new StringBuilder();
		in.init(System.in);
		PrintWriter out = new PrintWriter(System.out);
		BufferedReader inp = new BufferedReader(
				new InputStreamReader(System.in));
		int n = in.nextInt();
		int k = in.nextInt();
		graph = new ArrayList[n + 1];
		for (int i = 0; i < n+1; i++) {
			graph[i]=new ArrayList();
		}
		first = new HashSet();
		second = new HashSet();
		vis = new boolean[n + 1];
		int x[] = new int[k];
		int y[] = new int[k];
		for (int i = 0; i < k; i++) {
			int o = in.nextInt();
			int t = in.nextInt();
			graph[o].add(t);
			graph[t].add(o);
			x[i] = o;
			y[i] = t;

		}
		for (int i = 1; i <= n; i++) {
			if (!vis[i]) {
				solve(i, 0);
			}
		}
		for (int i = 0; i < k; i++) {
			if (!first.contains(x[i]) && !first.contains(y[i])) {
				System.out.println(-1);
				return;
			}
			if (!second.contains(x[i]) && !second.contains(y[i])) {
				System.out.println(-1);
				return;
			}
		}
		out.println(first.size());
		for (int i : first) {
			out.print(i + " ");
		}
		out.println();
		out.println(second.size());
		for (int i : second) {
			out.print(i + " ");
		}
		out.println();

		out.close();

	}
}