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:
//package sept;
 
import java.io.*;
import java.util.*;
 
public class TimePass {
    InputStream is;
    PrintWriter out;
    String INPUT = "";
    //boolean codechef=true;
    // String prodKey = "Av#/lL{OyEKiLR+/Ce%(w]^J65;XZe8FVb]]<931_=80E[BVnU^@4xu*J%KG3,CRqIZrUN~JJ+*6QC*CyBd>'$;>O"onO.bQ%{L}";
    boolean codechef=true;
    
    void solve()
    {
        int t=ni();
        while(t-->0){
            int n=ni();
            ArrayList<String> s0 = new ArrayList<>();
            ArrayList<String> s1 = new ArrayList<>();
            for(int i=0;i<3;i++){
                String s=ns();
                int cnt0=0;
                for(int j=0;j<2*n;j++) {
                    if (s.charAt(j)=='0') {
                        cnt0++;
                    }
                }
                if (cnt0>=n) {
                    s0.add(s);
                } else {
                    s1.add(s);
                }
            }
            if (s0.size() >= 2) {
                out.println(go(s0.get(0),s0.get(1),'0'));
            } else {
                out.println(go(s1.get(0),s1.get(1),'1'));
            }
        }
    }
    static String go(String s1,String s2,char c) {
        int n=s1.length()/2;
        ArrayList<Integer> v1 = new ArrayList<>();
        ArrayList<Integer> v2 = new ArrayList<>();
        v1.add(-1);
        v2.add(-1);
        for (int i=0;i<2*n;i++) {
            if (s1.charAt(i)==c) {
                v1.add(i);
            }
            if (s2.charAt(i)==c) {
                v2.add(i);
            }
        }
        StringBuffer ans=new StringBuffer();
        for (int i=0;i<n;i++) {
            for(int ind=v1.get(i)+1;ind<v1.get(i+1);ind++) {
                ans.append(s1.charAt(ind));
            }
            for(int ind=v2.get(i)+1;ind<v2.get(i+1);ind++) {
                ans.append(s2.charAt(ind));
            }
            ans.append(c);
        }
        for(int ind=v1.get(n)+1;ind<2*n;ind++) {
            ans.append(s1.charAt(ind));
        }
        for(int ind=v2.get(n)+1;ind<2*n;ind++) {
            ans.append(s2.charAt(ind));
        }
        return ans.toString();
    }
    static long[][] dp;
    
    static long desc(int[] a,int l,int r) {
        if (l==r) return 0;
        if (dp[l][r]!=-1) return dp[l][r];
        dp[l][r] = a[r]-a[l] + Math.min(desc(a,l+1,r),desc(a,l,r-1));
        return dp[l][r];
    }
    
    static int getMax(int arr[], int n)
    {
        int mx = arr[0];
        for (int i = 1; i < n; i++)
            if (arr[i] > mx)
                mx = arr[i];
        return mx;
    }
 
    // A function to do counting sort of arr[] according to
    // the digit represented by exp.
    static void countSort(int arr[], int n, int exp)
    {
        int output[] = new int[n]; // output array
        int i;
        int count[] = new int[10];
        Arrays.fill(count, 0);
 
        // Store count of occurrences in count[]
        for (i = 0; i < n; i++)
            count[(arr[i] / exp) % 10]++;
 
        // Change count[i] so that count[i] now contains
        // actual position of this digit in output[]
        for (i = 1; i < 10; i++)
            count[i] += count[i - 1];
 
        // Build the output array
        for (i = n - 1; i >= 0; i--) {
            output[count[(arr[i] / exp) % 10] - 1] = arr[i];
            count[(arr[i] / exp) % 10]--;
        }
 
        // Copy the output array to arr[], so that arr[] now
        // contains sorted numbers according to curent digit
        for (i = 0; i < n; i++)
            arr[i] = output[i];
    }
 
    // The main function to that sorts arr[] of size n using
    // Radix Sort
    static void radixsort(int arr[], int n)
    {
        // Find the maximum number to know number of digits
        int m = getMax(arr, n);
 
        // Do counting sort for every digit. Note that
        // instead of passing digit number, exp is passed.
        // exp is 10^i where i is current digit number
        for (int exp = 1; m / exp > 0; exp *= 10)
            countSort(arr, n, exp);
    }
 
    static int MAX=1500;
    
    static int prime[], countdiv[]; 
    
    static int[] getDivisorsArray() {
        int n=20000005;
        int[] mind = new int[n];
        Arrays.fill(mind, -1);
        for(int i=2;i<n;i++){
            if (mind[i]==-1){
                for(int j=i;j<n;j+=i){
                    if (mind[j]==-1){
                        mind[j]=i;
                    }
                }
            }
        }
        // int[] nod = new int[n];
        // for(int i=2;i<n;i++){
        //     int prod = i/mind[i];
        //     if (mind[i] != mind[prod]) {
        //         nod[i] = nod[prod] + 1;
        //     } else {
        //         nod[i] = nod[prod];
        //     }
        // }
        return mind;
    }
      
    // Simple sieve to find smallest prime factors of numbers 
    // smaller than MAX 
    void SieveOfEratosthenes() 
    { 
        for (int i = 2; i * i < MAX; ++i) 
        { 
            if (prime[i]==0) 
                for (int j = i * i; j < MAX; j += i) 
                    prime[j] = i; 
        } 
      
        // Prime number will have same divisor 
        for (int i = 1; i < MAX; ++i) 
            if (prime[i]==0) 
                prime[i] = i; 
    } 
      
    // Returns length of the largest subsequence 
    // with GCD more than 1. 
    int largestGCDSubsequence(int arr[], int n) 
    { 
        int ans = 0; 
        for (int i=0; i < n; ++i) 
        { 
            int element = arr[i]; 
      
            // Fetch total unique prime divisor of element 
            while (element > 1) 
            { 
                int div = prime[element]; 
      
                // Increment count[] of Every unique divisor 
                // we get till now 
                ++countdiv[div]; 
      
                // Find maximum frequency of divisor 
                ans = Math.max(ans, countdiv[div]); 
      
                while (element % div==0) 
                    element /= div; 
            } 
        } 
      
        return ans; 
    } 
      
    
    static boolean check(int x)
    {
        char[] a=(""+x).toCharArray();
        int s=0;
        for(int i=0;i<a.length;i++)
        {
            s+=a[i]-'0';
            s%=3;
        }
        if(s==0)return true;
        return false;
    }
 
    static int[][] packD(int n,int[] from,int[] to)
    {
        int[][] g=new int[n][];
        int[] p=new int[n];
        for(int f:from)
        {
            p[f]++;
        }
        int m=from.length;
        for(int i=0;i<n;i++)
        {
            g[i]=new int[p[i]];
        }
        for(int i=0;i<m;i++)
        {
            g[from[i]][--p[from[i]]]=to[i];
        }
        return g;
    }
        
    static class Pair
    {
        int a,b;
        public Pair(int a,int b)
        {
            this.a=a;
            this.b=b;
        }
    }
    
    static long lcm(int a,int b)
    {
        long val=a;
        val*=b;
        return (val/gcd(a,b));
    }
    
    static long gcd(long a,long b)
    {
        if(a==0)return b;
        return gcd(b%a,a);
    }
    
    static int pow(int a, int b, int p)
    {
        long ans = 1, base = a;
        while (b!=0)
        {
            if ((b & 1)!=0)
            {
                ans *= base;
                ans%= p;
            }
            base *= base;
            base%= p;
            b >>= 1;
        }
        return (int)ans;
    }
 
    static int inv(int x, int p)
    {
        return pow(x, p - 2, p);
    }
 
    
    void run() throws Exception
    {
        if(codechef)oj=true;
        is = oj ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        
        long s = System.currentTimeMillis();
        solve();
        out.flush();
        tr(System.currentTimeMillis()-s+"ms");
    }
    
    public static void main(String[] args) throws Exception {new TimePass().run();}
    
    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;
    
    private int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }
    
    private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
    private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
    
    private double nd() { return Double.parseDouble(ns()); }
    private char nc() { return (char)skip(); }
    
    private String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    
    private char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }
    
    private char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }
    
    private int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }
    
    private int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private boolean oj = System.getProperty("ONLINE_JUDGE") != null;
    private void tr(Object... o) { if(!oj)System.out.println(Arrays.deepToString(o)); }
}