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.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Scanner;

public class NPHardProblem
{
    static ArrayList<Integer>[] arr;static int color[];static int v;static boolean b[];static ArrayList<Integer> al=new ArrayList<>();static int fail=0;
    static HashSet<Integer> red=new HashSet<>();static HashSet<Integer> blue=new HashSet<>();
    static class Reader
    {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;

        public Reader()
        {
            din = new DataInputStream(System.in);
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public Reader(String file_name) throws IOException
        {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public String readLine() throws IOException
        {
            byte[] buf = new byte[64]; // line length
            int cnt = 0, c;
            while ((c = read()) != -1)
            {
                if (c == '\n')
                    break;
                buf[cnt++] = (byte) c;
            }
            return new String(buf, 0, cnt);
        }

        public int nextInt() throws IOException
        {
            int ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do
            {
                ret = ret * 10 + c - '0';
            }  while ((c = read()) >= '0' && c <= '9');

            if (neg)
                return -ret;
            return ret;
        }

        public long nextLong() throws IOException
        {
            long ret = 0;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();
            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');
            if (neg)
                return -ret;
            return ret;
        }

        public double nextDouble() throws IOException
        {
            double ret = 0, div = 1;
            byte c = read();
            while (c <= ' ')
                c = read();
            boolean neg = (c == '-');
            if (neg)
                c = read();

            do {
                ret = ret * 10 + c - '0';
            }
            while ((c = read()) >= '0' && c <= '9');

            if (c == '.')
            {
                while ((c = read()) >= '0' && c <= '9')
                {
                    ret += (c - '0') / (div *= 10);
                }
            }

            if (neg)
                return -ret;
            return ret;
        }

        private void fillBuffer() throws IOException
        {
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE);
            if (bytesRead == -1)
                buffer[0] = -1;
        }

        private byte read() throws IOException
        {
            if (bufferPointer == bytesRead)
                fillBuffer();
            return buffer[bufferPointer++];
        }

        public void close() throws IOException
        {
            if (din == null)
                return;
            din.close();
        }
    }
    static class Graph
    {
        int v;
        Graph(int v)
        {
            this.v=v;
            arr=new ArrayList[v+1];
            for(int i=1;i<=v;i++)
            {
                arr[i]=new ArrayList<>();
            }
        }
    }
    public static void AddEdge(int src,int dest)
    {
        arr[src].add(dest);
        arr[dest].add(src);
    }
    public static void main(String args[])
    {
        Scanner sc=new Scanner(System.in);
        v=sc.nextInt();
        int m=sc.nextInt();
        Graph g=new Graph(v);
        color=new int[v+1];
        HashSet<Integer> hm=new HashSet<>();
        for(int i=0;i<m;i++)
        {
            int p=sc.nextInt();
            int q=sc.nextInt();
            hm.add(p);
            hm.add(q);
            AddEdge(p,q);
        }
        //ArrayList<Integer> arl=new ArrayList<>(hm);
        b=new boolean[v+1];
        for (Integer pk:hm
             ) {
            color[pk]=-1;
            al.add(pk);
            red.add(pk);
            break;
        }
        //bfs(hm);
        for(Integer r:hm)
        {
            if(!b[r])
            {
                red.add(r);
                dfs(r,-1);
            }
        }
        if(fail!=-1)
        {
            /*int a=0,b=0;
            for(int i=1;i<=v;i++)
            {
                if(color[i]==-1)
                {
                    a++;
                }
                else if(color[i]==1)
                {
                    b++;
                }
            }*/
            System.out.println(red.size());
            for(Integer a:red)
            {
                System.out.print(a+" ");
            }
            System.out.println();
            System.out.println(blue.size());
            for(Integer a:blue)
            {
                System.out.print(a+" ");
            }
        }
        else
        {
            System.out.println("-1");
        }
    }
    public static void dfs(int r,int col)
    {
        b[r]=true;
        for(Integer a:arr[r])
        {
            if(color[a]==0)
            {
                color[a]=-col;
                if(col==1)
                    red.add(a);
                else if(col==-1)
                {
                    blue.add(a);
                }
                dfs(a,color[a]);
            }
            else if(color[a]==col)
            {
                fail=-1;
            }
        }
    }
    public static void bfs(HashSet<Integer> arl) {
        int fans = 0;
        while(arl.size()>0)
        {
            if(al.size()==0)
            {
                for(Integer ap:arl) {
                    al.add(ap);
                    red.add(ap);
                    color[ap] = -1;
                    break;
                }
            }
            while (al.size()>0) {
            int curr=al.get(0);
            //System.out.println();
           // System.out.print(curr+": ");
            if (!b[curr]) {
                //al.add(curr);
                if(color[curr]==-1) {
                    //System.out.println("blue");
                    for (Integer a : arr[curr]) {
                        if (!b[a]) {
                            //System.out.print(a+" ");
                            color[a] = 1;
                            al.add(a);
                            blue.add(a);
                            arl.remove(new Integer(a));
                        } else if (color[curr] != (-1 * color[a])) {
                            fans = -1;
                        }
                    }
                }
                        else if(color[curr]==1)
                        {
                            //System.out.println("red");
                            for (Integer a : arr[curr]) {
                                if (!b[a]) {
                                   // System.out.println(a+" ");
                                    color[a] = -1;
                                    al.add(a);
                                    red.add(a);
                                    arl.remove(new Integer(a));
                                }
                                else if (color[curr] != (-1 * color[a])) {
                                    fans = -1;
                                }
                        }
                    }
                b[curr] = true;
                arl.remove(new Integer(curr));
                //al.remove(0);
                }
            al.remove(0);
            }
                /*System.out.println(al);
                System.out.print(arl);
                System.out.println("red : "+red);
                System.out.println("blue : "+blue);*/
        }
        /*for(int i=1;i<=v;i++)
        {
            System.out.print(color[i]+" ");
        }
        System.out.println();
        for(int i=1;i<=v;i++)
        {
            System.out.print(i+" ");
        }*/
        //System.out.println();
        if(fans!=-1)
        {
            /*int a=0,b=0;
            for(int i=1;i<=v;i++)
            {
                if(color[i]==-1)
                {
                    a++;
                }
                else if(color[i]==1)
                {
                    b++;
                }
            }*/
            System.out.println(red.size());
            for(Integer a:red)
            {
                System.out.print(a+" ");
            }
            System.out.println();
            System.out.println(blue.size());
            for(Integer a:blue)
            {
                System.out.print(a+" ");
            }
        }
        else
        {
            System.out.println("-1");
        }
    }
}