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.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.StringTokenizer;

public class Main {
    static int n, m;
    static int[] colour;
    static ArrayList<Integer>[] arr;

    public static void main(String[] args) throws Exception {
        Scanner scanner = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        //==================================================//
        //answer here:
        n = scanner.nextInt();
        m = scanner.nextInt();
        colour = new int[n];
        Arrays.fill(colour, -1);
        arr = new ArrayList[n];
        //construct the graph:
        for (int i = 0; i < n; i++) arr[i] = new ArrayList<>();
        for (int i = 0; i < m; i++) {
            int u = scanner.nextInt() - 1, v = scanner.nextInt() - 1;
            arr[u].add(v);
            arr[v].add(u);

        }
        for (int i = 0; i < n; i++) {
            if (colour[i] == -1) {
                colour[i] = 0;
                if (!dfs(i)) {
                    System.out.println(-1);
                    return;
                }
            }

        }
        StringBuilder a = new StringBuilder(), b = new StringBuilder();
        int k1 = 0, k2 = 0;
        for (int i = 0; i < n; i++) {
            if (colour[i] == 0) {
                k1++;
                a.append(i + 1 + " ");
            } else if (colour[i] == 1) {
                k2++;
                b.append(i + 1 + " ");
            }
        }
        out.println(k2);
        out.println(b);
        out.println(k1);
        out.println(a);

        //==================================================//
        out.close();
    }

    static boolean dfs(int u) {
        for (int v : arr[u]) {
            if (colour[v]==-1){
                colour[v] = colour[u] ^ 1;
                if (!dfs(v))
                    return false;
            } else if (colour[v] == colour[u])
                return false;
        }
        return true;
    }
}


class pair implements Comparable<pair> {
    int id;
    int val;

    public pair(int id, int val) {
        this.id = id;
        this.val = val;
    }

    @Override
    public int compareTo(pair o) {
        return 0;

    }

    public String toString() {
        return "";
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        pair pair = (pair) o;
        return true;
    }

}

class Scanner {
    StringTokenizer st;
    BufferedReader br;

    public Scanner(InputStream system) {
        br = new BufferedReader(new InputStreamReader(system));
    }

    public Scanner(String file) throws Exception {
        br = new BufferedReader(new FileReader(file));
    }

    public String next() throws IOException {
        while (st == null || !st.hasMoreTokens()) st = new StringTokenizer(br.readLine());
        return st.nextToken();
    }

    public String nextLine() throws IOException {
        return br.readLine();
    }

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

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

    public char nextChar() throws IOException {
        return next().charAt(0);
    }

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

    public boolean ready() throws IOException {
        return br.ready();
    }

    public void waitForInput() throws InterruptedException {
        Thread.sleep(3000);
    }

    int[] readArray(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    long[] readLongArray(int n) throws IOException {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    }
}