You are given a binary string of length n (i. e. a string consisting of n characters '0' and '1').

In one move you can swap two adjacent characters of the string. What is the lexicographically minimum possible string you can obtain from the given one if you can perform no more than k moves? It is possible that you do not perform any moves at all.

Note that you can swap the same pair of adjacent characters with indices i and i+1 arbitrary (possibly, zero) number of times. Each such swap is considered a separate move.

You have to answer q independent test cases.

Input

The first line of the input contains one integer q (1 ≤ q ≤ 10^4) — the number of test cases.

The first line of the test case contains two integers n and k (1 ≤ n ≤ 10^6, 1 ≤ k ≤ n^2) — the length of the string and the number of moves you can perform.

The second line of the test case contains one string consisting of n characters '0' and '1'.

It is guaranteed that the sum of n over all test cases does not exceed 10^6 (∑ n ≤ 10^6).

Output

For each test case, print the answer on it: the lexicographically minimum possible string of length n you can obtain from the given one if you can perform no more than k moves.

Example

Input


3
8 5
11011010
7 9
1111100
7 11
1111100


Output


01011110
0101111
0011111

Note

In the first example, you can change the string as follows: 1\underline{10}11010 → \underline{10}111010 → 0111\underline{10}10 → 011\underline{10}110 → 01\underline{10}1110 → 01011110. 

In the third example, there are enough operations to make the string sorted.
import java.util.*;
import java.math.*;
import java.io.*;
import java.lang.*;

public class Main {
    
	public static void main(String[] args) {
        FastReader sc = new FastReader();
        int t = sc.nextInt();
        while(t-- > 0)
        {
            int n = sc.nextInt();
            long k = sc.nextLong();
            char ch[] = sc.next().toCharArray();
            List<Integer> zeros = new ArrayList<>();
            for(int i=0;i<n;i++)
            {
                if(ch[i]=='0') zeros.add(i);
            }
            
            //So I have zeros at i;
            HashSet<Integer> hs = new HashSet<>();
            for(int i=0;i<zeros.size();i++)
            {
                if(k==0) break;
                int index = zeros.get(i); //this is the index of ith zero;
                int need = index - i; //This much moves are needed;
                int mov = (int)Math.min(need,k); //This much moves I can make;
                hs.add(need-mov+i);
                k = k-mov;
            }
           // System.out.println(Arrays.toString(hs.toArray()));
            StringBuffer bf = new StringBuffer("");
            int count=0;
            for(int i=0;i<n;i++)
            {
                if(hs.contains(i))
                {
                    if(ch[i]=='0') count++;
                    bf.append("0");
                }
                else if(ch[i]=='1')
                {
                    bf.append("1");
                }
                else if(ch[i]=='0' && count<hs.size())
                {
                    //Zeros I have put ahead;
                    bf.append("1");
                    count++;
                   // System.out.println("hello");
                }
                else
                {
                    bf.append("0");
                }
            }
            System.out.println(bf.toString());
        }
        
        
    }
    
    
    
    
    
    
    
    
    public static int sum(int a[])
    {
        int sum=0;
        for(int i: a) sum=sum+i;
        return sum;
    }
    
  
    public static int getMax(int a[])
    {
        int m=Integer.MIN_VALUE;
        for(int i: a) m=Math.max(i,m);
        return m;
    }
    
    static class Pair
    {
        int x;
        int y;

        //int i;
        public Pair(int x, int  y)
        {
            this.x=x;
            this.y=y;
        }
    }
    static class Comp implements Comparator<Pair>
    {
        public int compare(Pair p1, Pair p2)
        {
            if(p1.y!=p2.y)
            {
                return p2.y - p1.y;
            }
            return p2.x - p1.x;
        }
    }
    public static int bs(long num[], long x)
    {
        int low=0;
        int high=num.length-1;
        int ans=-1;
        while(low<=high)
        {
            int mid = low + (high-low)/2;
            if(num[mid]==x)
            {
                ans = mid;
                high=mid-1;
            }
            else if(num[mid]<x)
            {
               // ans=mid;
                low=mid+1;
            }
            else
            {
                ans=mid;
                high=mid-1;
            }
        }
        return ans;
    }
    
    
    public static int partition(int arr[], int low, int high) 
    { 
        int pivot = arr[high];  
        int i = (low-1);
        for (int j=low; j<high; j++) 
        { 
            if (arr[j] < pivot) 
            { 
                i++; 
                int temp = arr[i]; 
                arr[i] = arr[j]; 
                arr[j] = temp; 
            } 
        } 
        int temp = arr[i+1]; 
        arr[i+1] = arr[high]; 
        arr[high] = temp; 
  
        return i+1; 
    } 
    public static void sort(int arr[], int low, int high) 
    { 
        if (low < high) 
        { 
            int pi = partition(arr, low, high); 
            sort(arr, low, pi-1); 
            sort(arr, pi+1, high); 
        } 
    } 
    
    
    
    
    
    
    static long gcd(long a,long b)
    {
        if(b==0) return a;
        return gcd(b,a%b);
    }
    
    
    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 void sort(long[] a) {
		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 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 (final 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 (final IOException e) {
				e.printStackTrace();
			}
			return str;
		}

		int[] nextIntArray(final int n) {
			final int a[] = new int[n];
			for (int i = 0; i < n; i++) {
				a[i] = Integer.parseInt(next());
			}
			return a;
		}

	}	
}
//private ArrayList<String[]> action = new ArrayList<String[]>();


//Templates for Comparator and Classes - @jagrit_07
/*
Arrays.sort(newEmployees, new Comparator<Employee>() {
    @Override
    public int compare(Employee emp1, Employee emp2) {
        return emp1.getName().compareTo(emp2.getName());
    }
});
class Pair
	{
		
		long i; //index;
		long l; //left;
		long c; //cost;
		public Pair(long x,long y,long z)
		{
			this.i=x;
			this.l=y;
			this.c=z;
		}
		public String toString()
		{
			return this.i+" "+this.l+" "+this.c;
		}
	}
class Comp implements Comparator<Pair>
	{
		public int compare(Pair p1, Pair p2)
		{
			if(p1.c!=p2.c)
			{
				return (int)(p1.c-p2.c); //sort acc to cost;
			}
			else{
				return (int)(p1.i-p2.i); //sort acc to index;
			}
			
		}
	}
*/

/*
System.out.println( 
      String.format("%.5f", b)); 
  HashMap - Put template - d.put(a1,d.getOrDefault(a1,0)+1);
  for (Map.Entry<String, Integer> entry : map.entrySet()) {
        System.out.println(entry.getKey() + ":" + entry.getValue());
    }
  Deque<String> deque 
            = new LinkedList<String>();  
            
  List<Integer> c[] = new ArrayList[3];          
*/