Problem: James Bond has a new plan for catching his enemy. There are some cities and directed roads between them, such that it is possible to travel between any two cities using these roads. When the enemy appears in some city, Bond knows her next destination but has no idea which path she will choose to move there. 

The city a is called interesting, if for each city b, there is exactly one simple path from a to b. By a simple path, we understand a sequence of distinct cities, such that for every two neighboring cities, there exists a directed road from the first to the second city. 

Bond's enemy is the mistress of escapes, so only the chase started in an interesting city gives the possibility of catching her. James wants to arrange his people in such cities. However, if there are not enough interesting cities, the whole action doesn't make sense since Bond's people may wait too long for the enemy.

You are responsible for finding all the interesting cities or saying that there is not enough of them. By not enough, James means strictly less than 20\% of all cities. 

Input

The first line contains one integer t (1 ≤ t ≤ 2 000) — the number of test cases. Each test case is described as follows:

The first line contains two integers n and m (1 ≤ n ≤ 10^5, 0 ≤ m ≤ 2 ⋅ 10^5) — the number of cities and roads between them. Each of the following m lines contains two integers u, v (u ≠ v; 1 ≤ u, v ≤ n), which denote that there is a directed road from u to v.

You can assume that between each ordered pair of cities there is at most one road. The sum of n over all test cases doesn't exceed 10^5, and the sum of m doesn't exceed 2 ⋅ 10^5.

Output

If strictly less than 20\% of all cities are interesting, print -1. Otherwise, let k be the number of interesting cities. Print k distinct integers in increasing order — the indices of interesting cities.

Example

Input


4
3 3
1 2
2 3
3 1
3 6
1 2
2 1
2 3
3 2
1 3
3 1
7 10
1 2
2 3
3 1
1 4
4 5
5 1
4 6
6 7
7 4
6 1
6 8
1 2
2 3
3 4
4 5
5 6
6 1
6 2
5 1


Output


1 2 3 
-1
1 2 3 5 
-1

Note

In all drawings, if a city is colored green, then it is interesting; otherwise, it is colored red.

In the first sample, each city is interesting. 

<image>

In the second sample, no city is interesting. 

<image>

In the third sample, cities 1, 2, 3 and 5 are interesting. 

<image>

In the last sample, only the city 1 is interesting. It is strictly less than 20\% of all cities, so the answer is -1. 

<image>

Solution (in JAVA):

Solution:
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.BufferedWriter;
import java.util.Set;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.stream.Stream;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.Collections;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author lewin
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        HJamesAndTheChase solver = new HJamesAndTheChase();
        int testCount = Integer.parseInt(in.next());
        for (int i = 1; i <= testCount; i++)
            solver.solve(i, in, out);
        out.close();
    }

    static class HJamesAndTheChase {
        int n;
        int m;
        List<Integer>[] graph;
        int[] depth;
        int[] low;
        int[] vis;
        int[] backcount;
        int vidx;
        boolean[] anc;
        boolean[] ok;
        int[] st;

        boolean dfs(int node) {
            vis[node] = vidx;
            anc[node] = true;
            low[node] = depth[node];
            for (int next : graph[node]) {
                if (vis[next] == vidx) {
                    if (!anc[next]) return false;
                    low[node] = Math.min(low[node], depth[next]);
                } else {
                    depth[next] = depth[node] + 1;
                    if (!dfs(next)) return false;
                    low[node] = Math.min(low[node], low[next]);
                }
            }
            anc[node] = false;
            return true;
        }

        int dfs2(int node) {
            vis[node] = vidx;
            int c = 0;
            for (int next : graph[node]) {
                if (vis[next] == vidx) {
                    c++;
                    backcount[next]++;
                } else {
                    c += dfs2(next);
                }
            }
            c -= backcount[node];
            ok[node] = c <= 1;
            return c;
        }

        void dfs3(int node) {
            vis[node] = vidx;
            st[depth[node]] = node;
            ok[node] &= ok[st[low[node]]];
            for (int next : graph[node]) {
                if (vis[next] != vidx) {
                    dfs3(next);
                }
            }
        }

        public void solve(int testNumber, InputReader in, OutputWriter out) {
            n = in.nextInt();
            m = in.nextInt();
            graph = LUtils.genArrayList(n);
            for (int i = 0; i < m; i++) {
                int a = in.nextInt() - 1, b = in.nextInt() - 1;
                graph[a].add(b);
            }
            low = new int[n];
            depth = new int[n];
            ok = new boolean[n];
            vis = new int[n];
            st = new int[n];
            anc = new boolean[n];
            backcount = new int[n];

            List<List<Integer>> scc = SCCKosaraju.scc(graph);
            List<Integer>[] dg = SCCKosaraju.sccGraph(graph, scc);
            int[] indeg = new int[n];
            for (int i = 0; i < dg.length; i++) {
                for (int x : dg[i]) {
                    indeg[x]++;
                }
            }
            for (int i = 1; i < dg.length; i++) {
                if (indeg[i] == 0) {
                    out.println(-1);
                    return;
                }
            }
            List<Integer> good = scc.get(0);
            Collections.shuffle(good);
            for (int itt = 0; itt < Math.min(good.size(), 40); itt++) {
                vidx++;
                Arrays.fill(anc, false);
                int k = good.get(itt);
                depth[k] = 0;
                if (dfs(k)) {
                    vidx++;
                    dfs2(k);
                    vidx++;
                    dfs3(k);
                    List<Integer> ans = new ArrayList<>();
                    for (int i : scc.get(0)) {
                        if (ok[i]) {
                            ans.add(i + 1);
                        }
                    }
                    Collections.sort(ans);
                    if (ans.size() * 5 >= n) {
                        boolean first = true;
                        for (int tk : ans) {
                            if (!first) out.print(" ");
                            first = false;
                            out.print(tk);
                        }
                        out.println();
                    } else {
                        out.println(-1);
                    }
                    return;
                }
            }
            out.println(-1);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1 << 16];
        private int curChar;
        private int numChars;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (this.numChars == -1) {
                throw new InputMismatchException();
            } else {
                if (this.curChar >= this.numChars) {
                    this.curChar = 0;

                    try {
                        this.numChars = this.stream.read(this.buf);
                    } catch (IOException var2) {
                        throw new InputMismatchException();
                    }

                    if (this.numChars <= 0) {
                        return -1;
                    }
                }

                return this.buf[this.curChar++];
            }
        }

        public int nextInt() {
            int c;
            for (c = this.read(); isSpaceChar(c); c = this.read()) {
                ;
            }

            byte sgn = 1;
            if (c == 45) {
                sgn = -1;
                c = this.read();
            }

            int res = 0;

            while (c >= 48 && c <= 57) {
                res *= 10;
                res += c - 48;
                c = this.read();
                if (isSpaceChar(c)) {
                    return res * sgn;
                }
            }

            throw new InputMismatchException();
        }

        public String next() {
            int c;
            while (isSpaceChar(c = this.read())) {
                ;
            }

            StringBuilder result = new StringBuilder();
            result.appendCodePoint(c);

            while (!isSpaceChar(c = this.read())) {
                result.appendCodePoint(c);
            }

            return result.toString();
        }

        public static boolean isSpaceChar(int c) {
            return c == 32 || c == 10 || c == 13 || c == 9 || c == -1;
        }

    }

    static class SCCKosaraju {
        public static List<List<Integer>> scc(List<Integer>[] graph) {
            int n = graph.length;
            boolean[] used = new boolean[n];
            List<Integer> order = new ArrayList<>();
            for (int i = 0; i < n; i++)
                if (!used[i])
                    dfs(graph, used, order, i);

            List<Integer>[] reverseGraph = Stream.generate(ArrayList::new).limit(n).toArray(List[]::new);
            for (int i = 0; i < n; i++)
                for (int j : graph[i])
                    reverseGraph[j].add(i);

            List<List<Integer>> components = new ArrayList<>();
            Arrays.fill(used, false);
            Collections.reverse(order);

            for (int u : order)
                if (!used[u]) {
                    List<Integer> component = new ArrayList<>();
                    dfs(reverseGraph, used, component, u);
                    components.add(component);
                }

            return components;
        }

        static void dfs(List<Integer>[] graph, boolean[] used, List<Integer> res, int u) {
            used[u] = true;
            for (int v : graph[u])
                if (!used[v])
                    dfs(graph, used, res, v);
            res.add(u);
        }

        public static List<Integer>[] sccGraph(List<Integer>[] graph, List<List<Integer>> components) {
            int[] comp = new int[graph.length];
            for (int i = 0; i < components.size(); i++)
                for (int u : components.get(i))
                    comp[u] = i;
            List<Integer>[] g = Stream.generate(ArrayList::new).limit(components.size()).toArray(List[]::new);
            Set<Long> edges = new HashSet<>();
            for (int u = 0; u < graph.length; u++)
                for (int v : graph[u])
                    if (comp[u] != comp[v] && edges.add(((long) comp[u] << 32) + comp[v]))
                        g[comp[u]].add(comp[v]);
            return g;
        }

    }

    static class LUtils {
        public static <E> List<E>[] genArrayList(int size) {
            return Stream.generate(ArrayList::new).limit(size).toArray(List[]::new);
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void print(Object... objects) {
            for (int i = 0; i < objects.length; i++) {
                if (i != 0) {
                    writer.print(' ');
                }
                writer.print(objects[i]);
            }
        }

        public void println() {
            writer.println();
        }

        public void close() {
            writer.close();
        }

        public void print(int i) {
            writer.print(i);
        }

        public void println(int i) {
            writer.println(i);
        }

    }
}