Problem: A bitstring is a string that contains only the characters 0 and 1.

Koyomi Kanou is working hard towards her dream of becoming a writer. To practice, she decided to participate in the Binary Novel Writing Contest. The writing prompt for the contest consists of three bitstrings of length 2n. A valid novel for the contest is a bitstring of length at most 3n that contains at least two of the three given strings as subsequences.

Koyomi has just received the three prompt strings from the contest organizers. Help her write a valid novel for the contest.

A string a is a subsequence of a string b if a can be obtained from b by deletion of several (possibly, zero) characters.

Input

The first line contains a single integer t (1 ≤ t ≤ 10^4) — the number of test cases.

The first line of each test case contains a single integer n (1 ≤ n ≤ 10^5).

Each of the following three lines contains a bitstring of length 2n. It is guaranteed that these three strings are pairwise distinct.

It is guaranteed that the sum of n across all test cases does not exceed 10^5.

Output

For each test case, print a single line containing a bitstring of length at most 3n that has at least two of the given bitstrings as subsequences.

It can be proven that under the constraints of the problem, such a bitstring always exists.

If there are multiple possible answers, you may output any of them.

Example

Input


2
1
00
11
01
3
011001
111010
010001


Output


010
011001010

Note

In the first test case, the bitstrings 00 and 01 are subsequences of the output string: 010 and 010. Note that 11 is not a subsequence of the output string, but this is not required.

In the second test case all three input strings are subsequences of the output string: 011001010, 011001010 and 011001010.

Solution (in JAVA):

Solution:
import java.io.*;
import java.util.*;
import java.util.ArrayList;
import java.util.Arrays.*;
import java.util.Map.Entry;

import static java.util.Collections.*;
import static java.lang.Math.*;
import static java.util.Arrays.*;

public class Solution {
    static final int SCAN_LINE_LENGTH = 1_000_002;
    private static final boolean thread = false;
    @SuppressWarnings("all")
    static final boolean HAS_TEST_CASES = (1 == 1) ? true : false;

    static int n, a[], e[][], vis[], m, b[];
    @SuppressWarnings("all")
    private static ArrayList<Integer> adj[], v = new ArrayList<>();
    static long gcd = 1;
    static HashMap<Integer, Integer> pos;

    @SuppressWarnings("unchecked")
    static void solve() throws Exception {
        n = ni();
        char[][] s = new char[3][];
        for (int i = 0; i < s.length; i++) {
            s[i] = ns();
        }
        int[] p = new int[3];
        StringBuffer sb = new StringBuffer();
        out: while (true) {
            for (int i = 0; i < p.length; i++) {
                if (p[i] == s[0].length)
                    break out;
            }
            int o = 0, z = 0;
            for (int i = 0; i < p.length; i++) {
                if (s[i][p[i]] == '0')
                    z++;
                else
                    o++;
            }
            if (o > z) {
                sb.append('1');
                for (int i = 0; i < p.length; i++) {
                    if (s[i][p[i]] == '1') {
                        p[i]++;
                    }
                }
            } else {
                sb.append('0');
                for (int i = 0; i < p.length; i++) {
                    if (s[i][p[i]] == '0') {
                        p[i]++;
                    }
                }
            }
        }
        int idx = -1, idxv = -1, c = 0;
        for (int i = 0; i < p.length; i++) {
            if (p[i] != s[0].length && idxv < p[i]) {
                idxv = p[i];
                idx = i;
            }
            if (p[i] == s[0].length)
                c++;

        }
        if (idx != -1 && c == 1)
            while (p[idx] != s[idx].length) {
                sb.append(s[idx][p[idx]++]);
            }

        pn(sb.toString());
    }

    public static void main(final String[] args) throws Exception {
        if (!thread) {
            final int testcases = HAS_TEST_CASES ? ni() : 1;
            for (int i = 1; i <= testcases; i++) {
                // pni(i + " t");
                // out.print("Case #" + (i) + ": ");
                try {
                    solve();
                } catch (final Exception e) {
                    // pni("idk Exception");
                    // e.printStackTrace(System.err);
                    // System.exit(0);
                    throw e;
                }
            }
            out.flush();
        }
        r.close();
        out.close();
    }

    @SuppressWarnings("all")
    private static final int MOD = (int) (1e9 + 7), MOD_FFT = 998244353;
    private static final Reader r = new Reader();
    private static final PrintWriter out = new PrintWriter(new BufferedOutputStream(System.out));

    public static long[] enumPows(int a, int n, int mod) {
        a %= mod;
        long[] pows = new long[n + 1];
        pows[0] = 1;
        for (int i = 1; i <= n; i++)
            pows[i] = pows[i - 1] * a % mod;
        return pows;
    }

    @SuppressWarnings("all")
    private static boolean eq(long a, long b) {
        return Long.compare(a, b) == 0;
    }

    @SuppressWarnings("all")
    private static ArrayList<Integer> seive(int n) {
        ArrayList<Integer> p = new ArrayList<>();
        int[] f = new int[n + 1];
        for (int i = 2; i <= n; i++) {
            if (f[i] == 1)
                continue;
            for (int j = i * i; j <= n && j < f.length; j += i) {
                f[j] = 1;
            }
        }
        for (int i = 2; i < f.length; i++) {
            if (f[i] == 0)
                p.add(i);
        }
        return p;
    }

    @SuppressWarnings("all")
    private static void s(int[] a) {
        Integer[] t = new Integer[a.length];
        for (int i = 0; i < t.length; i++) {
            t[i] = a[i];
        }
        sort(t);
        for (int i = 0; i < t.length; i++) {
            a[i] = t[i];
        }
    }

    int pow(int a, int b, int m) {
        int ans = 1;
        while (b != 0) {
            if ((b & 1) != 0)
                ans = (ans * a) % m;
            b /= 2;
            a = (a * a) % m;
        }
        return ans;
    }

    int modinv(int k) {
        return pow(k, MOD - 2, MOD);
    }

    @SuppressWarnings("all")
    private static void swap(final int i, final int j) {
        final int temp = a[i];
        a[i] = a[j];
        a[j] = temp;
    }

    @SuppressWarnings("all")
    private static boolean isMulOverflow(final long A, final long B) {
        if (A == 0 || B == 0)
            return false;
        final long result = A * B;
        if (A == result / B)
            return true;
        return false;
    }

    @SuppressWarnings("all")
    private static int gcd(final int a, final int b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }

    @SuppressWarnings("all")
    private static long gcd(final long a, final long b) {
        if (b == 0)
            return a;
        return gcd(b, a % b);
    }

    @SuppressWarnings("all")
    private static class Pair<T, E> implements Comparable<Pair<T, E>> {
        T fir;
        E snd;

        Pair() {
        }

        Pair(final T x, final E y) {
            this.fir = x;
            this.snd = y;
        }

        // @Override
        // @SuppressWarnings("unchecked")
        // public int compareTo(final Pair<T, E> o) {
        // final int c = ((Comparable<T>) fir).compareTo(o.fir);
        // return c != 0 ? c : ((Comparable<E>) snd).compareTo(o.snd);
        // }
        @Override
        @SuppressWarnings("unchecked")
        public int compareTo(final Pair<T, E> o) {
            final int c = ((Comparable<T>) fir).compareTo(o.fir);
            return c;
        }

    }

    @SuppressWarnings("all")
    private static class pi implements Comparable<pi> {
        int fir, snd;

        pi() {
        }

        pi(final int a, final int b) {
            fir = a;
            snd = b;
        }

        public int compareTo(final pi o) {
            return fir == o.fir ? snd - o.snd : fir - o.fir;
        }

        @Override
        public int hashCode() {
            final int prime = 31;
            int result = 1;
            result = prime * result + fir;
            result = prime * result + snd;
            return result;
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj)
                return true;
            if (obj == null)
                return false;
            if (getClass() != obj.getClass())
                return false;
            pi other = (pi) obj;
            if (fir != other.fir)
                return false;
            if (snd != other.snd)
                return false;
            return true;
        }

    }

    @SuppressWarnings("all")
    private static <T> void checkV(final Vector<T> adj[], final int i) {
        adj[i] = adj[i] == null ? new Vector<>() : adj[i];
    }

    private static <T> void checkV(final ArrayList<T> adj[], final int i) {
        adj[i] = adj[i] == null ? new ArrayList<>() : adj[i];
    }

    @SuppressWarnings("all")
    private static int[] na(final int n) throws Exception {
        final int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = ni();
        }
        return a;
    }

    @SuppressWarnings("all")
    private static int[] na1(final int n) throws Exception {
        final int[] a = new int[n + 1];
        for (int i = 1; i < a.length; i++) {
            a[i] = ni();
        }
        return a;
    }

    @SuppressWarnings("all")
    private static String n() throws IOException {
        return r.readToken();
    }

    @SuppressWarnings("all")
    private static char[] ns() throws IOException {
        return r.readToken().toCharArray();
    }

    @SuppressWarnings("all")
    private static String nln() throws IOException {
        return r.readLine();
    }

    private static int ni() throws IOException {
        return r.nextInt();
    }

    @SuppressWarnings("all")
    private static long nl() throws IOException {
        return r.nextLong();
    }

    @SuppressWarnings("all")
    private static double nd() throws IOException {
        return r.nextDouble();
    }

    @SuppressWarnings("all")
    private static void p(final Object o) {
        out.print(o);
    }

    @SuppressWarnings("all")
    private static void pn(final Object o) {
        out.println(o);
    }

    @SuppressWarnings("all")
    private static void pn() {
        out.println("");
    }

    @SuppressWarnings("all")
    private static void pi(final Object o) {
        out.print(o);
        out.flush();
    }

    @SuppressWarnings("all")
    private static void pni() {
        out.println("");
        out.flush();
    }

    private static void pni(final Object o) {
        out.println(o);
        out.flush();
    }

    private static class Reader {
        private final int BUFFER_SIZE = 1 << 17;
        private final DataInputStream din;
        private final byte[] buffer;
        private int bufferPointer, bytesRead;
        // private StringTokenizer st;

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

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

        final byte[] buf = new byte[SCAN_LINE_LENGTH];

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

        public String readToken() throws IOException {
            int cnt = 0;
            int c;
            o: while ((c = read()) != -1) {
                if (!(c >= 33 && c <= 126))
                    if (cnt == 0)
                        continue o;
                    else
                        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();
            final 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();
            final 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();
            final 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 {
    // if (thread)
    // new Thread(null, new Runnable() {
    // @Override
    // public void run() {
    // try {
    // final int testcases = HAS_TEST_CASES ? ni() : 1;
    // for (int i = 1; i <= testcases; i++) {
    // // out.print("Case #" + (i + 1) + ": ");
    // try {
    // solve();
    // } catch (final ArrayIndexOutOfBoundsException e) {
    // e.printStackTrace(System.err);
    // System.exit(-1);
    // } catch (final Exception e) {
    // pni("idk Exception in solve");
    // e.printStackTrace(System.err);
    // System.exit(-1);
    // }
    // }
    // out.flush();
    // } catch (final Throwable t) {
    // t.printStackTrace(System.err);
    // System.exit(-1);
    // }
    // }
    // }, "rec", (1L << 28)).start();
    // }

    @SuppressWarnings({ "all", })
    private static <T> T deepCopy(final T old) {
        try {
            return (T) deepCopyObject(old);
        } catch (final IOException | ClassNotFoundException e) {
            e.printStackTrace(System.err);
            System.exit(-1);
        }
        return null;
    }

    private static Object deepCopyObject(final Object oldObj) throws IOException, ClassNotFoundException {
        ObjectOutputStream oos = null;
        ObjectInputStream ois = null;
        try {
            final ByteArrayOutputStream bos = new ByteArrayOutputStream(); // A
            oos = new ObjectOutputStream(bos); // B
            // serialize and pass the object
            oos.writeObject(oldObj); // C
            oos.flush(); // D
            final ByteArrayInputStream bin = new ByteArrayInputStream(bos.toByteArray()); // E
            ois = new ObjectInputStream(bin); // F
            // return the new object
            return ois.readObject(); // G
        } catch (final ClassNotFoundException e) {
            pni("Exception in ObjectCloner = " + e);
            throw (e);
        } finally {
            oos.close();
            ois.close();
        }
    }

}