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.DataInputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

public class Main {

    private static int n;

    private static void run() throws IOException {
        n = in.nextInt();
        char[][] s = new char[3][];
        boolean[] more_0 = new boolean[3];
        for (int i = 0; i < 3; i++) {
            s[i] = in.next().toCharArray();
            int count = 0;
            for (int j = 0; j < 2 * n; j++) {
                if (s[i][j] == '0') count++;
            }
            more_0[i] = count >= n;
        }

        for (int i = 0; i < 3; i++) {
            for (int j = i + 1; j < 3; j++) {
                if (more_0[i] != more_0[j]) continue;
                char[] ans = build(s[i], s[j], more_0[i] ? '0' : '1');
                out.println(new String(ans));
                return;
            }
        }
        throw new RuntimeException();
    }

    private static char[] build(char[] s1, char[] s2, char base) {
        char[] ans = new char[n * 3];
        int index = 0;
        int p1 = 0;
        int p2 = 0;
        while (index < 3 * n) {
            while (p1 < 2 * n && s1[p1] != base) {
                ans[index++] = s1[p1++];
            }
            while (p2 < 2 * n && s2[p2] != base) {
                ans[index++] = s2[p2++];
            }
            if (index < 3 * n) {
                ans[index++] = base;
            }
            p1++;
            p2++;
        }
        return ans;
    }

    public static void main(String[] args) throws IOException {
        in = new Reader();
        out = new PrintWriter(new OutputStreamWriter(System.out));

        int t = in.nextInt();
        for (int i = 0; i < t; i++) {
            run();
        }

        out.flush();
        in.close();
        out.close();
    }

    private static int gcd(int a, int b) {
        if (a == 0 || b == 0)
            return 0;
        while (b != 0) {
            int tmp;
            tmp = a % b;
            a = b;
            b = tmp;
        }
        return a;
    }

    static final long mod = 1000000007;

    static long pow_mod(long a, long b) {
        long result = 1;
        while (b != 0) {
            if ((b & 1) != 0) result = (result * a) % mod;
            a = (a * a) % mod;
            b >>= 1;
        }
        return result;
    }

    private static long multiplied_mod(long... longs) {
        long ans = 1;
        for (long now : longs) {
            ans = (ans * now) % mod;
        }
        return ans;
    }

    @SuppressWarnings("FieldCanBeLocal")
    private static Reader in;
    private static PrintWriter out;

    private static void print_array(int[] array) {
        for (int now : array) {
            out.print(now);
            out.print(' ');
        }
        out.println();
    }

    private static void print_array(long[] array) {
        for (long now : array) {
            out.print(now);
            out.print(' ');
        }
        out.println();
    }

    static class Reader {
        private static final int BUFFER_SIZE = 1 << 16;
        private final DataInputStream din;
        private final byte[] buffer;
        private int bufferPointer, bytesRead;

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

        public String readLine() throws IOException {
            final byte[] buf = new byte[1024]; // 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 nextSign() throws IOException {
            byte c = read();
            while ('+' != c && '-' != c) {
                c = read();
            }
            return '+' == c ? 0 : 1;
        }

        private static boolean isSpaceChar(int c) {
            return !(c >= 33 && c <= 126);
        }

        public int skip() throws IOException {
            int b;
            // noinspection ALL
            while ((b = read()) != -1 && isSpaceChar(b)) {
                ;
            }
            return b;
        }

        public char nc() throws IOException {
            return (char) skip();
        }

        public String next() throws IOException {
            int b = skip();
            final StringBuilder sb = new StringBuilder();
            while (!isSpaceChar(b)) { // when nextLine, (isSpaceChar(b) && b != ' ')
                sb.appendCodePoint(b);
                b = read();
            }
            return sb.toString();
        }

        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 {
            din.close();
        }

    }
}