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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeMap;



public class Main {
	 
    public static void main(String[] args) {
    	
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        solve(in, out);
        out.close();
    }
 
    static String reverse(String s) {
        return (new StringBuilder(s)).reverse().toString();
    }

    static void sieveOfEratosthenes(int n, int factors[]) 
    { 
       n=1000000001;
    	factors[1]=1;
        for(int p = 2; p*p <=n; p++) 
        { 
            if(factors[p] == 0) 
            { 
                factors[p]=p;
                for(int i = p*p; i <= n; i += p) 
                    factors[i] = p; 
            } 
        } 
    }

    static void sort(int ar[]) {
        int n = ar.length;
        ArrayList<Integer> a = new ArrayList<>();
        for (int i = 0; i < n; i++)
            a.add(ar[i]);
        Collections.sort(a);
        for (int i = 0; i < n; i++)
            ar[i] = a.get(i);
    }

    static void sort1(long ar[]) {
        int n = ar.length;
        ArrayList<Long> a = new ArrayList<>();
        for (int i = 0; i < n; i++)
            a.add(ar[i]);
        Collections.sort(a);
        for (int i = 0; i < n; i++)
            ar[i] = a.get(i);
    }

    static long ncr(long n, long r, long mod) {
        if (r == 0)
            return 1;
        long val = ncr(n - 1, r - 1, mod);
        val = (n * val) % mod;
        val = (val * modInverse(r, mod)) % mod;
        return val;
    }
    public static int convert(String a, String b)
    {
    	int T=0;
    	if(b.charAt(0)=='P')
    	{
    		if(a.charAt(0)=='1'&&a.charAt(1)=='2') T=12;
    		else
    			T=(a.charAt(0)-'0')*10+(a.charAt(1)-'0')+12;
    	}
    	else if(b.charAt(0)=='A')
    	{
    		if(a.charAt(0)=='1'&&a.charAt(1)=='2') T=0;
    		else
    			T=(a.charAt(0)-'0')*10+(a.charAt(1)-'0');
    	}
    		
    	T=T*100+(a.charAt(3)-'0')*10+(a.charAt(4)-'0');
    	return T;
    	
    }
    static boolean areBracketsBalanced(String expr) 
    { 
        // Using ArrayDeque is faster than using Stack class 
        Deque<Character> stack 
            = new ArrayDeque<Character>(); 
  
        // Traversing the Expression 
        for (int i = 0; i < expr.length(); i++)  
        { 
            char x = expr.charAt(i); 
  
            if (x == '(' || x == '[' || x == '{')  
            { 
                // Push the element in the stack 
                stack.push(x); 
                continue; 
            } 
  
            // IF current current character is not opening 
            // bracket, then it must be closing. So stack 
            // cannot be empty at this point. 
            if (stack.isEmpty()) 
                return false; 
            char check; 
            switch (x) { 
            case ')': 
                check = stack.pop(); 
                if (check == '{' || check == '[') 
                    return false; 
                break; 
  
            case '}': 
                check = stack.pop(); 
                if (check == '(' || check == '[') 
                    return false; 
                break; 
  
            case ']': 
                check = stack.pop(); 
                if (check == '(' || check == '{') 
                    return false; 
                break; 
            } 
        } 
  
        // Check Empty Stack 
        return (stack.isEmpty()); 
    } 
    public static int hr(String s)
    {
    	int hh=0;
    	hh=(s.charAt(0)-'0')*10+(s.charAt(1)-'0');
    	return hh;
    }
    public static int mn(String s)
    {
    	int mm=0;
    	mm=(s.charAt(3)-'0')*10+(s.charAt(4)-'0');
    	return mm;
    }
	
	/*
	 * public static void countNumberOfPrimeFactors(){ boolean flag[]=new
	 * boolean[N]; Arrays.fill(flag,true); for(int i=2;i<N;i++){ if(flag[i]){
	 * for(int j=i;j<N;j+=i) { prime[j]++; flag[j]=false; } } } // prime[1]=1; }
	 */	 

   

	
	public static String rev(String s)
	{
		char[] temp=s.toCharArray();
		for(int i=0;i<s.length()/2;i++)
		{
			char tmp=temp[i];
			temp[i]=temp[s.length()-1-i];
			temp[s.length()-1-i]=tmp;
			
		}
		String str="";
		for(char ch: temp)
		{
			str+=ch;
		}
		return str;
	}
	static boolean isP(String str)
    {
 
        // Pointers pointing to the beginning
        // and the end of the string
        int i = 0, j = str.length() - 1;
 
        // While there are characters to compare
        while (i < j) {
 
            // If there is a mismatch
            if (str.charAt(i) != str.charAt(j))
                return false;
 
            // Increment first pointer and
            // decrement the other
            i++;
            j--;
        }
 
        // Given string is a palindrome
        return true;
    }
	public static boolean isSorted(List<Integer> l)
	{
		int n=l.size(),i=0;
		for(i=1;i<l.size();i++)
		{
			if(l.get(i-1)<l.get(i)) return false;
		}
		return true;
	}

public static boolean ln(long n, int c)
{
	int l=0;
	long t=n;
	while(t!=0)
	{
		
		t/=10;
		l++;
	}
	return l==c;
}
//final static int a[]=new int[2000];

	
  
    public static void solve(InputReader sc, PrintWriter pw) {
    	int t=sc.nextInt();
    while(t-->0) {
     	int n=sc.nextInt();
        String a=sc.next();
        String b=sc.next();
        String c=sc.next();
        int i=0,j=0,k=0;
        StringBuilder f=new StringBuilder();
        int l=0;
        while(i!=2*n&&j!=2*n&&k!=2*n)
        {
        	char ch='8';
        	int cnt=0;
        	if(a.charAt(i)=='0') cnt++;
        	if(b.charAt(j)=='0') cnt++;
        	if(c.charAt(k)=='0') cnt++;
        	
        	
        	if(cnt>=2)
        	{
        		f.append('0');
        		ch='0';
        	}
        	else
        	{
        		f.append('1');
        		ch='1';
        	}
        	if(a.charAt(i)==ch) i++;
        	if(b.charAt(j)==ch) j++;
        	if(c.charAt(k)==ch) k++;
        	
        	l++;
        	
        }
        if(i!=2*n&&2*n-i<=3*n-l) f.append(a.substring(i));
        else if(j!=2*n&&2*n-j<=3*n-l) f.append(b.substring(j));
        else if(k!=2*n&&2*n-k<=3*n-l) f.append(c.substring(k));
        
     pw.print(f+"\n");
     		
     		
     		
     	
   	 }
        
    }

	static class Pair1 {
        long a;
        long b;
        
        Pair1(long a, long b) {
            this.a = a;
            this.b = b;
        }
    }

    static class Pair implements Comparable<Pair> {
        int a;
        int b;
        
        Pair(int a, int b) {
            this.a = a;
            this.b = b;
        }
 
        public int compareTo(Pair p) {
            if(a!=p.a)
                return p.a-a;
            return b-p.b;
        }
    }

    static boolean isPrime(long n) {
        if (n <= 1)
            return false;
        if (n <= 3)
            return true;
        if (n % 2 == 0 || n % 3 == 0)
            return false;
        for (int i = 5; i * i <= n; i = i + 6)
            if (n % i == 0 || n % (i + 2) == 0)
                return false;
        return true;
    }

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

    static long fast_pow(long base, long n, long M) {
        if (n == 0)
            return 1;
        if (n == 1)
            return base % M;
        long halfn = fast_pow(base, n / 2, M);
        if (n % 2 == 0)
            return (halfn * halfn) % M;
        else
            return (((halfn * halfn) % M) * base) % M;
    }

    static long modInverse(long n, long M) {
        return fast_pow(n, M - 2, M);
    }
    public static int LowerBound(int a[], int x) 
	   {
			  int l=-1,r=a.length;
			  while(l+1<r) {
			    int m=(l+r)>>>1;
			    if(a[m]>=x) r=m;
			    else l=m;
			  }
			  return r;
		}
	
	   
	public static int UpperBound(int a[], int x) 
		{
		    int l=-1, r=a.length;
		    while(l+1<r) {
		       int m=(l+r)>>>1;
		       if(a[m]<=x) l=m;
		       else r=m;
		    }
		    return l+1;
		}

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String nextLine() {
			// TODO Auto-generated method stub
			return null;
		}

		public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }
    }
}