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.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.*;
import java.io.*;
import java.math.*;
public class Main6{

static class Pair
    { 
        int x;
		int y;
        public Pair(int x, int y) 
        {     
            this.x=x;
			this.y=y;
        }     
        
    @Override
            public int hashCode() 
            { 
                final int temp = 14; 
                int ans = 1; 
                ans =x*31+y*13; 
                return ans; 
            } 
      
            // Equal objects must produce the same 
            // hash code as long as they are equal 
        @Override
        public boolean equals(Object o) 
        { 
            if (this == o) { 
                return true; 
            } 
            if (o == null) { 
                return false; 
            } 
            if (this.getClass() != o.getClass()) { 
                return false; 
            } 
            Pair other = (Pair)o; 
            if (this.x != other.x || this.y!=other.y) { 
                return false; 
            } 
            return true; 
        } 
            
    } 
static class Pair1{
	int x;
	int y;
	long z;
	Pair1(int x, int y, long z)
	{
		this.x=x;
		this.y=y;
		this.z=z;
	}
}
    
    public static long pow(long a, long b)
    {
        long result=1;
        while(b>0)
        {
            if (b % 2 != 0)
            {
                result=(result*a)%1000000007;
                b--;
            } 
            a=(a*a)%1000000007;
            b /= 2;
        }   
        return result;
    }
    public static long fact(long num)
    {
                long value=1;
                int i=0;
                for(i=2;i<num;i++)
                {
                    value=((value%mod)*i%mod)%mod;
                }
                return value;
            }
            public static long gcd(long a, long b)
            {
                if (a == 0)
                    return b;
                return gcd(b%a, a);
            }
            
    /*        public static long lcm(long a,long b)
            {
                return a * (b / gcd(a, b));
            }
        */    public static long sum(int h)
            {
                return (h*(h+1)/2);
            }
        /*   public static void dfs(int parent,boolean[] visited,int[] dp)
            {
                ArrayList<Integer> arr=new ArrayList<Integer>();
                arr=graph.get(parent);
                visited[parent]=true;
                for(int i=0;i<arr.size();i++)
                {
                    int num=(int)arr.get(i);
                    if(visited[num]==false)
                    {
                        dfs(num,visited,dp);
                    }
                    dp[parent]=Math.max(dp[num]+1,dp[parent]);
                }
            }
        //    static int flag1=0;
            static int[] dis;*/
            static int mod=1000000007;
            static ArrayList<ArrayList<Integer>> graph;
            static ArrayList<ArrayList<Integer>> g;
            
       /*    public static void bfs(int num,int size)
            {
                boolean[] visited=new boolean[size+1];
                Queue<Integer> q=new LinkedList<>();
                q.add(num);
                ans[num]=1;
                visited[num]=true;
                while(!q.isEmpty())
                {
                    int x=q.poll();
                    ArrayList<Integer> al=graph.get(x);
                    for(int i=0;i<al.size();i++)
                    {
                        int y=al.get(i);    
                        if(visited[y]==false)
                        {
                            q.add(y);
                            ans[y]=ans[x]+1;
                            visited[y]=true;
                        }
                    }
                }
            }
            static int[] ans;*/
            
            
            
            
            
            
            
            
            
        //    static int[] a;              
            public static int[] sort(int[] a)
            {
                int n=a.length;
                ArrayList<Integer> ar=new ArrayList<>();
                for(int i=0;i<a.length;i++)
                {
                    ar.add(a[i]);
                }
                Collections.sort(ar);
                for(int i=0;i<n;i++)
                {
                    a[i]=ar.get(i);
                }
                return a;
            }
	/*		static class pqcomparator implements Comparator<Pair>
			{
				public int compare(Pair p1 ,Pair p2)
				{
					if(p1.y>p2.y)
					{
						return -1;
					}
					else
						return 1;
				}
			}
		*/	public static void dfs(int parent,boolean[] visited)
            {
                ArrayList<Integer> arr=new ArrayList<Integer>();
                arr=graph.get(parent);
                visited[parent]=true;
				ar.add(parent);
				count++;
				for(int i=0;i<arr.size();i++)
                {
					int num=(int)arr.get(i);
                    if(visited[num]==false)
                    {
						dfs(num,visited);
                    }
            	 }
            }
			static int count=0;
			static ArrayList<Integer> ar;
			static public void main(String args[])throws IOException
            {
				int t=i();
				//StringBuilder sb=new StringBuilder();
				while(t-->0)
				{
					int n=i();
					long k=l();
					String s=s();
					StringBuilder sb=new StringBuilder();
					long move=0,shift=0;
					long count=0,rem=0;
					int flag=-1;
					int ans=0;
					for(int i=0;i<s.length();i++)
					{
						if(s.charAt(i)=='1')
						{
							count++;
						}
						else
						{
							if(move+count<=k)
							{
								move+=count;
								ans++;
								shift++;
							}
							else
							{
								rem=k-move;
								move=k+1;
								break;
							}
						}
					}
					for(int i=0;i<(int)shift;i++)
					{
						sb.append("0");
					}
					count=0;
					for(int i=0;i<n;i++)
					{
						if(s.charAt(i)=='0')
						{
							if(count<shift)
							{
								count++;
							}
							else
							{
								sb.append("0");
							}
						}
						else
						{
							sb.append("1");
						}
					}
					if(rem>0)
					{
						String s2=sb.toString();
						StringBuilder sb1=new StringBuilder();
						int tt=0;
						for(int i=0;i<n;i++)
						{
							if(s2.charAt(i)=='0')
								tt++;
							if(tt==ans+1)
							{
								sb1.replace(i-(int)rem,i-(int)rem+1,"0");
								sb1.append("1");
								tt++;
							}
							else
							{
								sb1.append(s2.charAt(i));
							}
						//	pln(sb1+"");
						}
						pln(sb1.toString());
					}
					else
						pln(sb.toString());
				}
			//	System.out.print(sb.toString());
			}
            /**/
            static InputReader in=new InputReader(System.in);
                static OutputWriter out=new OutputWriter(System.out);
                public static long l()
                {
                    String s=in.String();
                    return Long.parseLong(s);
                }
                public static void pln(String value)
                {
                    System.out.println(value);
                }
                public static int i()
                {
                    return in.Int();
                }
                public static String s()
                {
                    return in.String();
                }
    }
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
         
        class InputReader {
             
            private InputStream stream;
            private byte[] buf = new byte[1024];
            private int curChar;
            private int numChars;
            private SpaceCharFilter filter;
         
            public InputReader(InputStream stream) {
                this.stream = stream;
            }
         
            public int read() {
                if (numChars== -1)
                    throw new InputMismatchException();
                if (curChar >= numChars) {
                    curChar = 0;
                    try {
                        numChars = stream.read(buf);
                    } catch (IOException e) {
                        throw new InputMismatchException();
                    }
                    if (numChars <= 0)
                        return -1;
                }
                return buf[curChar++];
            }
         
            public int Int() {
                int c = read();
                while (isSpaceChar(c))
                    c = read();
                int sgn = 1;
                if (c == '-') {
                    sgn = -1;
                    c = read();
                }
                int res = 0;
                do {
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    res *= 10;
                    res += c - '0';
                    c = read();
                } while (!isSpaceChar(c));
                return res * sgn;
            }
         
            public String String() {
                int c = read();
                while (isSpaceChar(c))
                    c = read();
                StringBuilder res = new StringBuilder();
                do {
                    res.appendCodePoint(c);
                    c = read();
                } while (!isSpaceChar(c));
                return res.toString();
            }
         
            public boolean isSpaceChar(int c) {
                if (filter != null)
                    return filter.isSpaceChar(c);
                return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
            }
         
            public String next() {
                return String();
            }
         
            public interface SpaceCharFilter {
                public boolean isSpaceChar(int ch);
            }
        }
         
        class OutputWriter {
            private final PrintWriter writer;
         
            public OutputWriter(OutputStream outputStream) {
                writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
            }
         
            public OutputWriter(Writer writer) {
                this.writer = new PrintWriter(writer);
            }
         
            public void print(Object...objects) {
                for (int i = 0; i < objects.length; i++) {
                    if (i != 0)
                        writer.print(' ');
                    writer.print(objects[i]);
                }
            }
         
            public void printLine(Object...objects) {
                print(objects);
                writer.println();
            }
         
            public void close() {
                writer.close();
            }
         
            public void flush() {
                writer.flush();
            }
         
            }
         
            class IOUtils {
         
            public static int[] readIntArray(InputReader in, int size) {
                int[] array = new int[size];
                for (int i = 0; i < size; i++)
                    array[i] = in.Int();
                return array;
            }
         
            } 

