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.util.*;
import java.io.*;
import java.util.stream.IntStream;

public class Main {

    static long startTime = System.currentTimeMillis();

    // for global initializations and methods starts here

    // global initialisations and methods end here

    static void run(){
    boolean tc = true;
    //AdityaFastIO r = new AdityaFastIO();
    FastReader r = new FastReader();

    try (OutputStream out = new BufferedOutputStream(System.out)) {

        //long startTime = System.currentTimeMillis();

        int testcases = tc ? r.ni() : 1;
        int tcCounter = 1;
        // Hold Here Sparky------------------->>>
        // Solution Starts Here

        start : while (testcases --> 0) {
            StringBuilder sb = new StringBuilder();

            int N = r.ni() << 1;
            char[] s1 = r.word().toCharArray();
            char[] s2 = r.word().toCharArray();
            char[] s3 = r.word().toCharArray();

            int count1 = 0;
            int count2 = 0;
            int count3 = 0;

            if (count1 < N) {
                do {
                    if (s1[count1] != s2[count2]) {
                        if (s2[count2] != s3[count3]) {
                            sb.append(s3[count3]);
                            count3++;
                            count1++;
                        } else {
                            sb.append(s2[count2]);
                            count2++;
                            count3++;
                        }
                    } else {
                        sb.append(s1[count1]);
                        count1++;
                        count2++;
                    }
                } while (count1 < N && count2 < N && count3 < N);
            }
            if (count2 != N) {
                if (count3 == N) {
                    count3 = count1;
                    s3 = s1;
                }
            } else {
                count2 = count1;
                s2 = s1;
            }

            if (count3 >= count2) {
                count2 = count3;
                s2 = s3;
            }

            while (count2 < N) sb.append(s2[count2++]);

            out.write((sb + " ").getBytes());
            out.write(("\n").getBytes());

        }
        // Solution Ends Here
    } catch (IOException e) {
        e.printStackTrace();
    }
}

    static class AdityaFastIO{
        final private int BUFFER_SIZE = 1<<16;
        private final DataInputStream din;
        private final byte[] buffer;
        private int bufferPointer, bytesRead;
        public BufferedReader br;
        public StringTokenizer st;

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

        public AdityaFastIO(String file_name) throws IOException {
            din = new DataInputStream(new FileInputStream(file_name));
            buffer = new byte[BUFFER_SIZE];
            bufferPointer = bytesRead = 0;
        }

        public String word() {
            while (st == null || !st.hasMoreElements()) {
                try { st = new StringTokenizer(br.readLine()); }
                catch (IOException e) { e.printStackTrace(); }
            }
            return st.nextToken();
        }

        public String line() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

        public String readLine() throws IOException {
            byte[] buf = new byte[100000001]; // 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 ni() throws IOException {
            int ret = 0;
            byte c = read();
            while (c <= ' ') c = read();
            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 nl() throws IOException {
            long ret = 0;byte c = read();
            while (c <= ' ') c = read();
            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 nd() throws IOException {
            double ret = 0, div = 1;byte c = read();
            while (c <= ' ') c = read();
            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();
        }
    }
    public static void main(String[] args) throws Exception {run();}

    static long mod = 998244353;
    static long modInv(long base, long e) {
    long result = 1;
    base %= mod;
    while (e>0) {
        if ((e & 1)>0) result = result * base % mod;
        base = base * base % mod;
        e >>= 1;
    }
    return result;
}

    static class FastReader {
        BufferedReader br;
        StringTokenizer st;
        public FastReader() { br = new BufferedReader(new InputStreamReader(System.in)); }
        String word() {
            while (st == null || !st.hasMoreElements()) {
                try { st = new StringTokenizer(br.readLine()); }
                catch (IOException e) { e.printStackTrace(); }
            }
            return st.nextToken();
        }
        String line() {
            String str = "";
            try { str = br.readLine(); }
            catch (IOException e) { e.printStackTrace(); }
            return str;
        }
        int ni() { return Integer.parseInt(word()); }
        long nl() { return Long.parseLong(word()); }
        double nd() { return Double.parseDouble(word()); }
    }

    static int MOD = (int) (1e9 + 7);

    static long powerLL(long x, long n) {
    long result = 1;
    while (n > 0) {
        if (n % 2 == 1) result = result * x % MOD;
        n = n / 2;x = x * x % MOD;
    }
    return result;
}

    static long powerStrings(int i1, int i2) {
    String sa = String.valueOf(i1);
    String sb = String.valueOf(i2);
    long a = 0, b = 0;
    for (int i = 0; i < sa.length(); i++) a = (a * 10 + (sa.charAt(i) - '0')) % MOD;
    for (int i = 0; i < sb.length(); i++) b = (b * 10 + (sb.charAt(i) - '0')) % (MOD - 1);
    return powerLL(a, b);
}

    static long gcd(long a, long b) { if (a == 0) return b;else return gcd(b % a, a); }
    static long lcm(long a, long b) { return (a * b) / gcd(a, b); }

    static long lower_bound(List<Long> list, long k) {
    int s = 0;
    int e = list.size();
    while (s != e) {
        int mid = (s + e) >> 1;
        if (list.get(mid) < k) s = mid + 1;
        else e = mid;
    }
    if (s == list.size()) return -1;
    return s;
}

    static int upper_bound(List<Long> list, long k) {
    int s = 0;
    int e = list.size();
    while (s != e) {
        int mid = (s + e) >> 1;
        if (list.get(mid) <= k) s = mid + 1;
        else e = mid;
    }
    if (s == list.size()) return -1; return s;
}

    static void addEdge(ArrayList<ArrayList<Integer>> graph, int edge1, int edge2) {
    graph.get(edge1).add(edge2);graph.get(edge2).add(edge1);
}

    public static class Pair implements Comparable<Pair> {
        int first;int second;
        public Pair(int first, int second) { this.first = first;this.second = second; }
        public String toString() { return "(" + first + "," + second + ")"; }
        public int compareTo(Pair o) {
            // TODO Auto-generated method stub
            if(this.first!=o.first)
                return (int) (this.first - o.first);
            else return(int)(this.second-o.second);
        }
    }

    public static class PairC<X,Y> implements Comparable<PairC> {
        X first;Y second;
        public PairC(X first, Y second) { this.first = first;this.second = second; }
        public String toString() { return "(" + first + "," + second + ")"; }
        public int compareTo(PairC o) {
            // TODO Auto-generated method stub
            return o.compareTo((PairC) first);
        }
    }

    static boolean isCollectionsSorted(List<Long> list) {
    if (list.size() == 0 || list.size() == 1) return true;
    for (int i = 1; i < list.size(); i++) if (list.get(i) <= list.get(i - 1)) return false;
    return true;
}

    static boolean isCollectionsSortedReverseOrder(List<Long> list) {
    if (list.size() == 0 || list.size() == 1) return true;
    for (int i = 1; i < list.size(); i++) if (list.get(i) >= list.get(i - 1)) return false;
    return true;
}

}