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.math.*;
import java.math.BigInteger;


public final class A
{    
	static StringBuilder ans=new StringBuilder();
	static FastReader in=new FastReader();
	static ArrayList<ArrayList<Integer>> g,tg;
	static long mod=(long)1e9+7;
	static boolean set[],col[]; 
	static int D[],par[];
	static char G[][];
	static int dp[][],max=0;
	static  HashMap<Integer,Long> buy,sell;
	//static Pair moves[]= {new Pair(-1,0),new Pair(1,0), new Pair(0,-1), new Pair(0,1)};
	public static void main(String args[])throws IOException
	{		
		int T=i();
		while(T-->0)
		{
			int N=i();
			char A[]=in.next().toCharArray();
			char B[]=in.next().toCharArray();
			char C[]=in.next().toCharArray();
			char a=f(A),b=f(B),c=f(C);
			if(a==b)
			{
				print(A,B,a);
			}
			else if(a==c)
			{
				print(A,C,a);
			}
			else
			{
				print(B,C,b);
			}
		}		
	}
	static void print(char A[],char B[],char x)
	{
		int a=0,b=0,s=0;
		ans=new StringBuilder();
		while(s*2<A.length)
		{
			while(A[a]!=x) 
			{
				ans.append(A[a]);
				a++;
			}
			while(B[b]!=x)
			{
				ans.append(B[b]);
				b++;
			}
			a++;
			b++;
			ans.append(x);
			s++;
		}
		while(a<A.length)
		{
			ans.append(A[a++]);
		}
		while(b<A.length)
		{
			ans.append(B[b++]);
		}
		System.out.println(ans);
	}
	static char f(char A[])
	{
		int z=0;
		for(char x:A)
			if(x=='0')z++;
		if(z*2>=A.length)return '0';
		else return '1';
	}
	static int lower(long A[],long x)
	{
		int l=-1,r=A.length;
		while(r-l>1)
		{
			int m=(l+r)/2;
			if(A[m]>=x)r=m;
			else l=m;				
		}
		return r;
	}
	static int upper(long A[],long x)
	{
		int l=-1,r=A.length;
		while(r-l>1)
		{
			int m=(l+r)/2;
			if(A[m]<=x)l=m;
			else r=m;
		}
		return l;
	}



	static boolean f(int a,int b,int c,int d)
	{
		if(a==b && a==c && a==d)return true;
		else return false;
	}
	static int max(int a ,int b,int c,int d)
	{
		a=Math.max(a, b);
		c=Math.max(c,d);
		return Math.max(a, c);
	}
	static int min(int a ,int b,int c,int d)
	{
		a=Math.min(a, b);
		c=Math.min(c,d);
		return Math.min(a, c);
	}


	static int find(int l,int r,long A[] ,long val)
	{
		int m=0;
		while(l<=r)
		{
			m=(l+r)/2;
			if(A[m]>=val)r=m-1;
			else l=m+1;
		}
		return m;
	}
	static void dfs(int n,int p)
	{
		par[n]=p;
		set[n]=true;
		for(int c:g.get(n))
		{
			if(!set[c])dfs(c,n);
		}
	}
	static HashMap<Integer,Integer> Hash(int A[])
	{
		HashMap<Integer,Integer> mp=new HashMap<>();
		for(int a:A)
		{
			int f=mp.getOrDefault(a,0)+1;
			mp.put(a, f);
		}
		return mp;
	}
	static long mul(long a, long b)
	{
		return ( a %mod * 1L * b%mod )%mod;
	}
	static void swap(int A[],int a,int b)
	{
		int t=A[a];
		A[a]=A[b];
		A[b]=t;
	}


	static int find(int a)
	{
		if(par[a]<0)return a;
		return par[a]=find(par[a]);
	}
	static void union(int a,int b)
	{
		a=find(a);
		b=find(b);
		int t=Math.min(a, b);
		b=Math.max(a, b);
		a=t;
		if(a!=b)
		{
			//			g.get(a).add(b);
			//			g.get(b).add(a);
			par[a]+=par[b];
			par[b]=a;
		}
	}
	static boolean isSorted(int A[])
	{
		for(int i=1; i<A.length; i++)
		{
			if(A[i]<A[i-1])return false;
		}
		return true;
	}

	static boolean isDivisible(StringBuilder X,int i,long num)
	{
		long r=0;
		for(; i<X.length(); i++)
		{
			r=r*10+(X.charAt(i)-'0');
			r=r%num;
		}
		return r==0;
	}    



	static int lower_Bound(int A[],int low,int high, int x) 
	{ 
		if (low > high) 
			if (x >= A[high]) 
				return A[high]; 

		int mid = (low + high) / 2; 

		if (A[mid] == x) 
			return A[mid]; 

		if (mid > 0 && A[mid - 1] <= x && x < A[mid]) 
			return A[mid - 1]; 

		if (x < A[mid]) 
			return lower_Bound( A, low, mid - 1, x); 

		return lower_Bound(A, mid + 1, high, x); 
	} 

	static String f(String A)
	{
		String X="";
		for(int i=A.length()-1; i>=0; i--)
		{
			int c=A.charAt(i)-'0';
			X+=(c+1)%2;
		}
		return X;
	}

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

	static String swap(String X,int i,int j)
	{
		char ch[]=X.toCharArray();
		char a=ch[i];
		ch[i]=ch[j];
		ch[j]=a;
		return new String(ch);
	}

	static int sD(long n)  
	{  

		if (n % 2 == 0 )  
			return 2;  

		for (int i = 3; i * i <= n; i += 2) {  
			if (n % i == 0 )  
				return i;  
		}  

		return (int)n;  
	}  

	static void setGraph(int N)
	{
		par=new int[N+1];
		D=new int[N+1];
		set=new boolean[N+1];
		g=new ArrayList<ArrayList<Integer>>();
		tg=new ArrayList<ArrayList<Integer>>();
		int inf=Integer.MAX_VALUE;
		for(int i=0; i<=N; i++)
		{

			g.add(new ArrayList<Integer>());
			tg.add(new ArrayList<Integer>());			
			D[i]=inf;
		}
	}



	static  long pow(long a,long b)
	{
		//long mod=1000000007;
		long pow=1;
		long x=a;
		while(b!=0)
		{
			if((b&1)!=0)pow=(pow*x)%mod;
			x=(x*x)%mod;
			b/=2;
		}
		return pow;
	}

	static long toggleBits(long x)//one's complement || Toggle bits
	{
		int n=(int)(Math.floor(Math.log(x)/Math.log(2)))+1;

		return ((1<<n)-1)^x;
	}

	static int countBits(long a)
	{
		return (int)(Math.log(a)/Math.log(2)+1);
	}

	static long fact(long N)
	{ 
		long n=2; 
		if(N<=1)return 1;
		else
		{
			for(int i=3; i<=N; i++)n=(n*i)%mod;
		}
		return n;
	}

	static int kadane(int A[])
	{
		int lsum=A[0],gsum=A[0];
		for(int i=1; i<A.length; i++)
		{
			lsum=Math.max(lsum+A[i],A[i]);
			gsum=Math.max(gsum,lsum);
		}
		return gsum;
	}

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

	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 void print(char A[])
	{
		for(char c:A)System.out.print(c+" ");
		System.out.println();
	}
	static void print(boolean A[])
	{
		for(boolean c:A)System.out.print(c+" ");
		System.out.println();
	}
	static void print(int A[])
	{
		for(int a:A)System.out.print(a+" ");
		System.out.println();	
	}
	static void print(long A[])
	{
		for(long i:A)System.out.print(i+ " ");
		System.out.println();

	}
	static void print(ArrayList<Integer> A)
	{
		for(int a:A)System.out.print(a+" ");
		System.out.println();
	}

	static int i()
	{
		return in.nextInt();
	}

	static long l()
	{
		return in.nextLong();
	}

	static int[] input(int N){
		int A[]=new int[N];
		for(int i=0; i<N; i++)
		{
			A[i]=in.nextInt();
		}
		return A;
	}

	static long[] inputLong(int N)     {
		long A[]=new long[N];
		for(int i=0; i<A.length; i++)A[i]=in.nextLong();
		return A;
	}

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

}
class cube implements Comparable<cube>
{
	boolean f;
	int p;
	long q;
	cube(long q,int p,boolean f)
	{
		this.q=q;
		this.p=p;
		this.f=f;
	}
	public int compareTo(cube X)
	{
		return X.p-this.p;
	}
}
//class pair implements Comparable<pair>
//{
//	long a;
//	int index;
//	pair(long x,int i)
//	{
//		a=x;
//		index=i;
//	}
//	public int compareTo(pair X)
//	{
//		if(this.a>X.a)return 1;
//		else if(this.a==X.a)return 0;
//		else return -1;
//	}
//}

//Code For FastReader
//Code For FastReader
//Code For FastReader
//Code For FastReader
class FastReader
{
	BufferedReader br;
	StringTokenizer st;
	public FastReader()
	{
		br=new BufferedReader(new InputStreamReader(System.in));
	}

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

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

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

	double nextDouble()
	{
		return Double.parseDouble(next());
	}

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

}