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.util.PriorityQueue;
import java.util.AbstractQueue;
import java.util.Random;
import java.util.ArrayList;
import java.util.AbstractCollection;
import java.io.OutputStreamWriter;
import java.io.OutputStream;
import java.util.Iterator;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.List;
import java.io.Closeable;
import java.io.Writer;
import java.util.Comparator;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) throws Exception {
        Thread thread = new Thread(null, new TaskAdapter(), "", 1 << 27);
        thread.start();
        thread.join();
    }

    static class TaskAdapter implements Runnable {
        @Override
        public void run() {
            InputStream inputStream = System.in;
            OutputStream outputStream = System.out;
            FastInput in = new FastInput(inputStream);
            FastOutput out = new FastOutput(outputStream);
            EJamesAndTheChase solver = new EJamesAndTheChase();
            int testCount = Integer.parseInt(in.next());
            for (int i = 1; i <= testCount; i++)
                solver.solve(i, in, out);
            out.close();
        }
    }

    static class EJamesAndTheChase {
        RandomWrapper rw = new RandomWrapper();
        boolean valid;

        public void solve(int testNumber, FastInput in, FastOutput out) {
            int n = in.readInt();
            int m = in.readInt();

            Node[] nodes = new Node[n];
            for (int i = 0; i < n; i++) {
                nodes[i] = new Node();
                nodes[i].id = i;
            }

            for (int i = 0; i < m; i++) {
                Node a = nodes[in.readInt() - 1];
                Node b = nodes[in.readInt() - 1];
                a.adj.add(b);
            }

            Node root = null;

            for (int i = 0; i < 50; i++) {
                Node randRoot = nodes[rw.nextInt(0, n - 1)];
                valid = true;
                for (Node node : nodes) {
                    node.visited = false;
                    node.instk = false;
                }

                dfs(randRoot, 0);
                for (Node node : nodes) {
                    valid = valid && node.visited;
                }

                if (!valid) {
                    continue;
                } else {
                    root = randRoot;
                    break;
                }
            }

            if (root == null) {
                out.println(-1);
                return;
            }

            //dfs and find root
            dpOnTree(root);
            root.ok = true;
            countOnTree(root);

            List<Node> interestingNodes = new ArrayList<>(n);
            for (Node node : nodes) {
                if (node.ok) {
                    interestingNodes.add(node);
                }
            }

            if (interestingNodes.size() * 5 < n) {
                out.println(-1);
                return;
            }

            //out.println(interestingNodes.size());
            for (Node node : interestingNodes) {
                out.append(node.id + 1).append(' ');
            }
            out.println();
        }

        public void countOnTree(Node root) {
            if (root.top != null && root.top.ok) {
                root.ok = true;
            }
            for (Node node : root.adj) {
                if (node.depth != root.depth + 1) {
                    continue;
                }
                countOnTree(node);
            }
        }

        public void dpOnTree(Node root) {
            for (Node node : root.adj) {
                if (node.depth != root.depth + 1) {
                    //to ancestor
                    root.pq.add(node);
                } else {
                    dpOnTree(node);
                    root.pq.addAll(node.pq);
                }
            }

            while (!root.pq.isEmpty() && root.pq.peekMax().depth >= root.depth) {
                root.pq.popMax();
            }

            if (root.pq.size() == 1) {
                root.top = root.pq.iterator().next();
            }
        }

        public void dfs(Node root, int depth) {
            if (root.visited) {
                valid = valid && root.instk;
                return;
            }

            root.visited = true;
            root.instk = true;
            root.depth = depth;

            for (Node node : root.adj) {
                dfs(node, depth + 1);
            }

            root.instk = false;
        }

    }

    static class FastInput {
        private final InputStream is;
        private StringBuilder defaultStringBuf = new StringBuilder(1 << 13);
        private byte[] buf = new byte[1 << 13];
        private int bufLen;
        private int bufOffset;
        private int next;

        public FastInput(InputStream is) {
            this.is = is;
        }

        private int read() {
            while (bufLen == bufOffset) {
                bufOffset = 0;
                try {
                    bufLen = is.read(buf);
                } catch (IOException e) {
                    bufLen = -1;
                }
                if (bufLen == -1) {
                    return -1;
                }
            }
            return buf[bufOffset++];
        }

        public void skipBlank() {
            while (next >= 0 && next <= 32) {
                next = read();
            }
        }

        public String next() {
            return readString();
        }

        public int readInt() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            int val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

        public String readString(StringBuilder builder) {
            skipBlank();

            while (next > 32) {
                builder.append((char) next);
                next = read();
            }

            return builder.toString();
        }

        public String readString() {
            defaultStringBuf.setLength(0);
            return readString(defaultStringBuf);
        }

    }

    static class RandomWrapper {
        private Random random;

        public RandomWrapper() {
            this(new Random());
        }

        public RandomWrapper(Random random) {
            this.random = random;
        }

        public int nextInt(int l, int r) {
            return random.nextInt(r - l + 1) + l;
        }

    }

    static class FastOutput implements AutoCloseable, Closeable, Appendable {
        private StringBuilder cache = new StringBuilder(10 << 20);
        private final Writer os;

        public FastOutput append(CharSequence csq) {
            cache.append(csq);
            return this;
        }

        public FastOutput append(CharSequence csq, int start, int end) {
            cache.append(csq, start, end);
            return this;
        }

        public FastOutput(Writer os) {
            this.os = os;
        }

        public FastOutput(OutputStream os) {
            this(new OutputStreamWriter(os));
        }

        public FastOutput append(char c) {
            cache.append(c);
            return this;
        }

        public FastOutput append(int c) {
            cache.append(c);
            return this;
        }

        public FastOutput println(int c) {
            return append(c).println();
        }

        public FastOutput println() {
            cache.append(System.lineSeparator());
            return this;
        }

        public FastOutput flush() {
            try {
                os.append(cache);
                os.flush();
                cache.setLength(0);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
            return this;
        }

        public void close() {
            flush();
            try {
                os.close();
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        public String toString() {
            return cache.toString();
        }

    }

    static class FixedMinCollection<V> extends AbstractCollection<V> {
        private PriorityQueue<V> pq;
        private int cap;
        private Comparator<V> comp;

        public FixedMinCollection(int cap, Comparator<V> comp) {
            if (cap == 0) {
                throw new IllegalArgumentException();
            }
            this.cap = cap;
            this.comp = comp;
            pq = new PriorityQueue<>(cap, comp.reversed());
        }

        public boolean add(V v) {
            if (pq.size() < cap) {
                pq.add(v);
                return true;
            }
            if (comp.compare(pq.peek(), v) > 0) {
                pq.remove();
                pq.add(v);
                return true;
            }
            return false;
        }

        public V peekMax() {
            return pq.peek();
        }

        public V popMax() {
            return pq.remove();
        }

        public void clear() {
            pq.clear();
        }

        public Iterator<V> iterator() {
            return pq.iterator();
        }

        public int size() {
            return pq.size();
        }

    }

    static class Node {
        List<Node> adj = new ArrayList<>();
        int id;
        boolean visited;
        boolean instk;
        int depth;
        Node top;
        boolean ok;
        static Comparator<Node> sortByDepth = (a, b) -> Integer.compare(a.depth, b.depth);
        FixedMinCollection<Node> pq = new FixedMinCollection<>(2, sortByDepth);

        public String toString() {
            return "" + (id + 1);
        }

    }
}