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.*; 
 public class B{
static int[] dx={-1,1,0,0};
static int[] dy={0,0,1,-1};
    static FastReader scan=new FastReader();
   public static PrintWriter out = new PrintWriter (new BufferedOutputStream(System.out));
  static ArrayList<Pair>es;
  static LinkedList<Integer>edges[];
  static LinkedList<Integer>edges2[];

   static boolean prime[];
   static void sieve(int n) 
    { 
        
        prime = new boolean[n+1]; 
        for(int i=0;i<n;i++) 
            prime[i] = true; 
          
        for(int p = 2; p*p <=n; p++) 
        { 
           
            if(prime[p] == true) 
            { 
                
                for(int i = p*p; i <= n; i += p) 
                    prime[i] = false; 
            } 
        } 
          
        
    }      
     public static int lowerBound(long[] array, int length, long value) {
        int low = 0;
        int high = length;
        while (low < high) {
            final int mid = (low + high) / 2;
            //checks if the value is less than middle element of the array
            if (value <= array[mid]) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }
        return low;
    }
    public static int upperBound(long[] array, int length, long value) {
        int low = 0;
        int high = length;
        while (low < high) {
            final int mid = low+(high-low) / 2;
            if ( array[mid]>value) {
                high = mid ;
            } else {
                low = mid+1;
            }
        }
        return low;
    }
static long mod(long x,long y)
    {
        if(x<0)
            x=x+(-x/y+1)*y;
        return x%y;
    }    
     static boolean isPowerOfTwo(long n) 
    { 
        if (n == 0) 
            return false; 
  
        while (n != 1) { 
            if (n % 2 != 0) 
                return false; 
            n = n / 2; 
        } 
        return true; 
    } 

  
   
static boolean isprime(long x)
           {
            for(long i=2;i*i<=x;i++)
                if(x%i==0)
                    return false;
                return true;
           }


static int dist(int x1,int y1,int x2,int y2){
return Math.abs(x1-x2)+Math.abs(y1-y2);
}


    static long cuberoot(long x)
    {
        long lo = 0, hi = 1000005;
        while(lo<hi)
        {
            long m = (lo+hi+1)/2;
            if(m*m*m>x)
                hi = m-1;
            else
                lo = m;
        }
        return lo;
    }
     public static int log2(int N) 
    { 
  
        // calculate log2 N indirectly 
        // using log() method 
        int result = (int)(Math.log(N) / Math.log(2)); 
  
        return result; 
    } 
  
    
   
       static long gcd(long a, long b) {
    if(a!=0&&b!=0)
        while((a%=b)!=0&&(b%=a)!=0);
    return a^b;
}
    static long LCM(long a,long b){
    return (Math.abs(a*b))/gcd(a,b);
   }
   static int mid;
   public static class comp1 implements Comparator<Pair>{  
public int compare(Pair o1,Pair o2){
    return (int)(o1.y-o2.y);
}
  }

     public static class comp2 implements Comparator<Pair>{  
public int compare(Pair o1,Pair o2){
 
return (int)((o1.x+o1.y*mid)-(o2.x+o2.y*mid));
}
  }
 static boolean can(int m,int s)
 {
    return (s>=0&&s<=m*9);
 }
   static boolean collinear(long x1, long y1, long x2,  
                          long y2, long x3, long y3) 
{
    long a = x1 * (y2 - y3) +  
                x2 * (y3 - y1) +  
                x3 * (y1 - y2); 
                if(a==0)
                    return true;
                return false;
}

 static void pythagoreanTriplets(int limit) 
    { 
   //ArrayList<Integer>res=new ArrayList<Integer>();
        // triplet: a^2 + b^2 = c^2 
        int a, b, c = 0; 
  
        // loop from 2 to max_limitit 
        int m = 2; 
  
        // Limiting c would limit 
        // all a, b and c 
        int cnt=0;
        int tmp=1;
        while (c < limit) { 
  
            // now loop on j from 1 to i-1 
            //System.out.println("FUCK");

            for ( int n=tmp; n < m; n++) { 
                // Evaluate and print 
                // triplets using 
                // the relation between 
                // a, b and c 
                a = m * m - n * n; 
                b = 2 * m * n; 
                c = m * m + n * n;
               // System.out.println("FUCK");



  
                if (c > limit) 
                    break; 
  
              // System.out.println(a + " " + b + " " + c); 
                if(c+b==c*c-b*b){
               //     out.println(n);
         /// out.println(a+" "+b+" "+c);
                cnt++;
            }
            }
        tmp++; 
            m++; 
        } 
        out.println(cnt);
    } 
  static int arr[];
  static int n,l;
  static boolean flag=false;
  static boolean vis[]=new boolean[(int)2e5+5];
  static int res[];
  static int idx=0;
  static StringBuilder s;
  static void dfs(int x)
  {
    
    vis[x]=true;
    res[idx++]=x;
    for(int v:edges[x])
        if(!vis[v])
            dfs(v);
  }
  static void swap(int i,int j)
  {
    char tmp=s.charAt(i);
    s.setCharAt(i,s.charAt(j));
    s.setCharAt(j,tmp);
  }
public static void main(String[] args)  throws Exception 
{
    /*int xx=253;
    for(int i=1;i*i<=xx;i++)
    {
        if(xx%i==0)
        {
            System.out.println(i);
            System.out.println(xx/i);
        }
    }*/
//java.util.Scanner scan=new java.util.Scanner(new File("mootube.in"));
// PrintWriter out = new PrintWriter (new FileWriter("mootube.out"));
//Scannen=new FastReader("moocast.in");
//out = new PrintWriter ("moocast.out");
//System.out.println(3^2);
//System.out.println(19%4);
   //StringBuilder news=new StringBuilder("ab");
   //news.deleteCharAt(1);
   //news.insert(0,'c');
   //news.deleteCharAt(0);
   //System.out.println(news);
   //System.out.println(can(2,15));
    //System.out.println(LCM(2,2));
  // System.out.println(31^15);
 //System.out.println("");
   //System.out.println(824924296372176000L>(long)1e16);
int tt=1;
//rec(2020);

//int st=scan.nextInt();
//System.out.println(calc(91));
//sieve(21000);

//SNWNSENSNNSWNNW

   // System.out.println(set.remove(new Pair(1,1)));
//System.out.println(count("cccccccccccccccccccccccccooooooooooooooooooooooooodddddddddddddeeeeeeeeeeeeeeeeeeeeeeeeeffffffffffffforrrrrrrrrrrrrcesssssssssssss","codeforces"));
  //S0ystem.out.println(isPowerOfTwo(446265625L));
//System.out.println("daaa".compareTo("bccc"));
//System.out.println(2999000999L>1999982505L);
tt=scan.nextInt();
  outer:while(tt-->0)
 { 
  int n=scan.nextInt();
  long k=scan.nextLong();
   s=new StringBuilder(scan.next());
   ArrayList<Integer>arr=new ArrayList<Integer>();
  for(int i=0;i<s.length();i++)
  {
    if(s.charAt(i)=='0')
        arr.add(i);
  }
  int a[]=new int[arr.size()];
  for(int i=0;i<arr.size();i++)
    a[i]=arr.get(i);
  for(int i=0;i<arr.size();i++)
  {
    if(k<=0)
        break;
    if(i==0)
    {
        //out.println("FUCK");
        if(a[i]!=0)
        {
          //  out.println("FUCK");
            if(k>=a[i])
            {
               // out.println("FUCK");
                k-=a[i];
                s.setCharAt(0,'0');
                s.setCharAt(a[i],'1');
                a[i]=0;
               // out.println(s);
            }
            else{
            s.setCharAt((int)(a[i]-k),'0');
            s.setCharAt((int)a[i],'1');
            k=0;
        }
        }
    }
    else 
    {
        if(k>=a[i]-a[i-1]-1)
        {
            if(a[i]-a[i-1]>1){
            k-=(a[i]-a[i-1]-1);
            s.setCharAt(a[i-1]+1,'0');
            s.setCharAt(a[i],'1');
            a[i]=a[i-1]+1;
        }
        }
        else if(k>0)
        {

            s.setCharAt((int)(a[i]-k),'0');
            s.setCharAt(a[i],'1');
            k=0;
        }
    }
  }
  out.println(s);

}




out.close();
}    


static class dsu{
    static int id[]=new int[101];
    dsu()
    {
        for(int i=0;i<101;i++)
            id[i]=i;
    }
    static int find(int x)
    {
        if(x==id[x])
            return x;
        return find(id[x]);
    }
    static void connect(int i,int j)
    {
        i=find(i);
        j=find(j);
        id[i]=j;
    }
    static boolean is(int i,int j)
    {
        return find(i)==find(j);
    }
}
static long binexp(long a,long n,long mod)
{
    if(n==0)
       return 1;
    long res=binexp(a,n/2,mod)%mod;
    res=res*res;
    if(n%2==1)
        return (res*a)%mod;
    else 
        return res%mod;
}
static class special{
    Pair x;
    Pair y;
    special(Pair x,Pair y)
    {
      this.x=new Pair(x.x,x.y);
      this.y=new Pair(y.x,y.y);
    }   
      @Override
        public int hashCode() {
            return (int)(x.x + 31 * y.y);
        }
        public boolean equals(Object other)
    {
        if(other instanceof special)
        {
            special e =(special)other;
            return this.x.x==e.x.x && this.x.y==e.x.y && this.y.x==e.y.x && this.y.y==e.y.y;
        }
        else return false;
    }
}
static long powMod(long base, long exp, long mod) {
       if (base == 0 || base == 1) return base;
       if (exp == 0) return 1;
       if (exp == 1) return base % mod;
       long R = powMod(base, exp/2, mod) % mod;
       R *= R;
       R %= mod;
       if ((exp & 1) == 1) {
           return base * R % mod;
       }
       else return R % mod;
   }
 public static  long pow(long b, long e) {
            long r = 1;
            while (e > 0) {
                if (e % 2 == 1) r = r * b ;
                b = b * b;
                e >>= 1;
            }
            return r;
        }

private static void sort(int[] arr) {
        List<Integer> list = new ArrayList<>();
        for (int object : arr) list.add(object);
        Collections.sort(list);
        for (int i = 0; i < list.size(); ++i) arr[i] = list.get(i);
    }
 public static class FastReader {
        BufferedReader br;
        StringTokenizer root;
        
 
        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
        FastReader(String filename)throws Exception
        {

            br=new BufferedReader(new FileReader(filename));
        }
 
        String next() {
            while (root == null || !root.hasMoreTokens()) {
                try {
                    root = new StringTokenizer(br.readLine());
                } catch (Exception addd) {
                    addd.printStackTrace();
                }
            }
            return root.nextToken();
        }
 
        int nextInt() {
            return Integer.parseInt(next());
        }
 
        double nextDouble() {
            return Double.parseDouble(next());
        }
 
        long nextLong() {
            return Long.parseLong(next());
        }
 
        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (Exception addd) {
                addd.printStackTrace();
            }
            return str;
        }
         public int[] nextIntArray(int arraySize) {
            int array[] = new int[arraySize];
 
            for (int i = 0; i < arraySize; i++) {
                array[i] = nextInt();
            }
 
            return array;
        }
}
public static class Pair implements Comparable<Pair>{
         int x;
         int y;
         long ab;
        
        int z;
        public Pair(){}
        public Pair(int x1, int y1,int z) {
            x=x1;
            y=y1;
            this.z=z;
        }
        public Pair(int x1, int y1) {
            x=x1;
            y=y1;
            this.ab=x+y;
        
        }
        @Override
        public int hashCode() {
            return (int)(x + 31 * y);
        }
        public String toString() {
            return x + " " + y;
        }
        @Override
        public boolean equals(Object o){
            if (o == this) return true;
            if (o.getClass() != getClass()) return false;
            Pair t = (Pair)o;
            return t.x == x && t.y == y;
        }
        public  int compareTo(Pair o)
        {
            if(x==o.x)
                return (int)(y-o.y);
            return (int)(x-o.x);
        }
}

}







