A binary string is a string where each character is either 0 or 1. Two binary strings a and b of equal length are similar, if they have the same character in some position (there exists an integer i such that a_i = b_i). For example:

  * 10010 and 01111 are similar (they have the same character in position 4); 
  * 10010 and 11111 are similar; 
  * 111 and 111 are similar; 
  * 0110 and 1001 are not similar. 



You are given an integer n and a binary string s consisting of 2n-1 characters. Let's denote s[l..r] as the contiguous substring of s starting with l-th character and ending with r-th character (in other words, s[l..r] = s_l s_{l + 1} s_{l + 2} ... s_r).

You have to construct a binary string w of length n which is similar to all of the following strings: s[1..n], s[2..n+1], s[3..n+2], ..., s[n..2n-1].

Input

The first line contains a single integer t (1 ≤ t ≤ 1000) — the number of test cases.

The first line of each test case contains a single integer n (1 ≤ n ≤ 50).

The second line of each test case contains the binary string s of length 2n - 1. Each character s_i is either 0 or 1.

Output

For each test case, print the corresponding binary string w of length n. If there are multiple such strings — print any of them. It can be shown that at least one string w meeting the constraints always exists.

Example

Input


4
1
1
3
00000
4
1110000
2
101


Output


1
000
1010
00

Note

The explanation of the sample case (equal characters in equal positions are bold):

The first test case: 

  * 1 is similar to s[1..1] = 1. 



The second test case: 

  * 000 is similar to s[1..3] = 000; 
  * 000 is similar to s[2..4] = 000; 
  * 000 is similar to s[3..5] = 000. 



The third test case: 

  * 1010 is similar to s[1..4] = 1110; 
  * 1010 is similar to s[2..5] = 1100; 
  * 1010 is similar to s[3..6] = 1000; 
  * 1010 is similar to s[4..7] = 0000. 



The fourth test case: 

  * 00 is similar to s[1..2] = 10; 
  * 00 is similar to s[2..3] = 01. 
import java.util.*;
import java.lang.String;
 import java.util.Arrays;
public class Main {
      
     static int largest(int arr[]) 
     { 
         int i; 
           

         int max = arr[0]; 
        
         for (i = 1; i < arr.length; i++) 
             if (arr[i] > max) 
                 max = arr[i]; 
        
         return max; 
     } 
      
     static int sum(int arr[]) 
     { 
         int sum = 0; 
         int i; 
        
         
         for (i = 0; i < arr.length; i++) 
            sum +=  arr[i]; 
        
         return sum; 
     }
    static int frequency(int a[], 
    int n, int x) 
    { 
        int count = 0; 
        for (int i=0; i < n; i++) 
        if (a[i] == x)  
            count++; 
        return count; 
    } 
      
 
    public static void main(String[] args) {
 
        Scanner in = new Scanner(System.in);
        int t = in.nextInt();
        int i,j,l=0,r,n,m,c=0,c2=0,x,y,z,p,q,s;
        long k;
        
        for(i=0;i<t;i++)
        {n=in.nextInt();
            in.nextLine();
            c=0;c2=0;
         String str=in.nextLine();
         for(j=0;j<str.length();j++)
         {if(str.charAt(j)=='1')
             c++;
             else
             c2++;
             
            }
      
        if(c>c2)
        {for(j=0;j<n;j++)
        System.out.print('1');}
        else
          { for(j=0;j<n;j++)
        System.out.print('0');}
         System.out.println();
        
         }
}}
       
