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 static java.lang.Double.parseDouble;
import static java.lang.Integer.bitCount;
import static java.lang.Integer.parseInt;
import static java.lang.Integer.reverse;
import static java.lang.Long.parseLong;
import static java.lang.Math.abs;
import static java.lang.Math.max;
import static java.lang.Math.min;
import static java.lang.System.exit;
import static java.util.Comparator.comparingInt;
import static java.util.Comparator.reverseOrder;
import static java.util.Map.Entry.comparingByValue;
import static java.util.stream.Collectors.toMap;
 
import java.io.*;
import java.lang.reflect.Array;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.*;
 
public class Solution {
 
    static BufferedReader in;
    static PrintWriter out;
    static StringTokenizer tok;

      void solve() throws Exception {
        int q = nextInt();
        while(q-->0) {
        	int n = nextInt(), treatedZeros = 0;
        	long k = nextLong();
        	char s[] = next().toCharArray(), ans[] = new char[n];
        	Arrays.fill(ans, '1');
        	List<Integer> zeroPos = new ArrayList();
        	for(int i = 0; i < n; i++) if(s[i] == '0') zeroPos.add(i);
        	for(int pos: zeroPos) {
        		if(treatedZeros + k >= pos) {
        			ans[treatedZeros] = '0';
        			k -= (pos - treatedZeros);
        			treatedZeros++;
        		} else {
        			pos -= k;
        			k = 0;
        			ans[pos] = '0';
        			treatedZeros++;
        		}
        		if(k == 0) break;
        	}
        	
        	for(int i = 0; i < n; i++) {
        		if(treatedZeros > 0) {
        			out.print(ans[i]);
        			if(s[i] == '0') treatedZeros--;
        		} else out.print(s[i]);
        	}
        	out.println();
        }
    }
 
    // call it like this: lower_bound(a, x + 1) ( /!\ + 1 )
    public static int lower_bound(int[] a, int v) {
        int low = -1, high = a.length;
        while (high - low > 1) {
            int h = high + low >>> 1;
            if (a[h] >= v) {
                high = h;
            } else {
                low = h;
            }
        }
        return high;
    }
 
    private String getFraction(int a, int b) {
        assert b != 0;
        String sign = (a > 0 && b > 0) || (a < 0) && (b < 0) ? "+" : "-";
        a = abs(a);
        b = abs(b);
        int gcd = gcd(a, b);
        return sign + (a / gcd) + "/" + (b / gcd);
    }
 
    private int gcd(int a, int b) {
        while (b > 0) {
            int temp = b;
            b = a % b;
            a = temp;
        }
        return a;
    }
 
    private int lcm(int a, int b) {
        return a * (b / gcd(a, b));
    }
 
    public static int[] radixSort(int[] f) {
        if (f.length < 100) {
            Arrays.sort(f);
            return f;
        }
        int[] to = new int[f.length];
        {
            int[] b = new int[65537];
            for (int i = 0; i < f.length; i++) b[1 + (f[i] & 0xffff)]++;
            for (int i = 1; i <= 65536; i++) b[i] += b[i - 1];
            for (int i = 0; i < f.length; i++) to[b[f[i] & 0xffff]++] = f[i];
            int[] d = f;
            f = to;
            to = d;
        }
        {
            int[] b = new int[65537];
            for (int i = 0; i < f.length; i++) b[1 + (f[i] >>> 16)]++;
            for (int i = 1; i <= 65536; i++) b[i] += b[i - 1];
            for (int i = 0; i < f.length; i++) to[b[f[i] >>> 16]++] = f[i];
            int[] d = f;
            f = to;
            to = d;
        }
        return f;
    }
 
    public static long pow(long a, long n, long mod) {
        long ret = 1;
        int x = 63 - Long.numberOfLeadingZeros(n);
        for (; x >= 0; x--) {
            ret = ret * ret % mod;
            if (n << 63 - x < 0)
                ret = ret * a % mod;
        }
        return ret;
    }
 
    public static boolean nextPermutation(Integer[] a) {
        int n = a.length;
        int i;
        for (i = n - 2; i >= 0 && a[i] >= a[i + 1]; i--) ;
        if (i == -1)
            return false;
        int j;
        for (j = i + 1; j < n && a[i] < a[j]; j++) ;
        int d = a[i];
        a[i] = a[j - 1];
        a[j - 1] = d;
        for (int p = i + 1, q = n - 1; p < q; p++, q--) {
            d = a[p];
            a[p] = a[q];
            a[q] = d;
        }
        return true;
    }
 
    void print(Object x) {
        out.print(String.valueOf(x));
        out.flush();
    }
 
    void println(Object x) {
        out.println(String.valueOf(x));
        out.flush();
    }
 
    // for Map with custom key/value, override toString in your custom class
    void printMap(Map map) {
        if (map.keySet().size() == 0) return;
        Object firstValue = map.keySet().iterator().next();
        if (map.get(firstValue) instanceof Queue || map.get(firstValue) instanceof List) {
            for (Object key : map.keySet()) {
                out.print(String.valueOf(key) + ": ");
                Collection values = (Collection) map.get(key);
                for (Object value : values) out.print(String.valueOf(value) + " ");
                out.println();
            }
        } else if (map.get(firstValue).getClass().isArray()) {
            for (Object key : map.keySet()) {
                out.print(String.valueOf(key) + ": ");
                Object[] values = (Object[]) map.get(key);
                for (Object value : values) out.print(String.valueOf(value) + " ");
                out.println();
            }
        } else {
            for (Object key : map.keySet()) {
                out.println(String.valueOf(key) + ": " + map.get(key));
            }
        }
    }
 
    private int[] na(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < n; i++) a[i] = nextInt();
        return a;
    }
 
    private long[] nal(int n) throws IOException {
        long[] a = new long[n];
        for (int i = 0; i < n; i++) a[i] = nextLong();
        return a;
    }
 
    int nextInt() throws IOException {
        return parseInt(next());
    }
 
    long nextLong() throws IOException {
        return parseLong(next());
    }
 
    double nextDouble() throws IOException {
        return parseDouble(next());
    }
 
    String next() throws IOException {
        while (tok == null || !tok.hasMoreTokens()) {
            tok = new StringTokenizer(in.readLine());
        }
        return tok.nextToken();
    }
 
    public static void main(String[] args) throws Exception {
        try {
            boolean isLocal = false;
            if (isLocal) {
                in = new BufferedReader(new FileReader("solution.in"));
                out = new PrintWriter(new BufferedWriter(new FileWriter("solution.out")));
            } else {
                in = new BufferedReader(new InputStreamReader(System.in));
                out = new PrintWriter(new OutputStreamWriter(System.out));
            }
 
            //long lStartTime = System.currentTimeMillis();
            new Solution().solve();
            //long lEndTime = System.currentTimeMillis();
            //out.println("Elapsed time in seconds: " + (double)(lEndTime - lStartTime) / 1000.0);
            in.close();
            out.close();
        } catch (Throwable e) {
            e.printStackTrace();
            exit(1);
        }
    }
}