You have n distinct points (x_1, y_1),…,(x_n,y_n) on the plane and a non-negative integer parameter k. Each point is a microscopic steel ball and k is the attract power of a ball when it's charged. The attract power is the same for all balls.

In one operation, you can select a ball i to charge it. Once charged, all balls with Manhattan distance at most k from ball i move to the position of ball i. Many balls may have the same coordinate after an operation.

More formally, for all balls j such that |x_i - x_j| + |y_i - y_j| ≤ k, we assign x_j:=x_i and y_j:=y_i.

<image> An example of an operation. After charging the ball in the center, two other balls move to its position. On the right side, the red dot in the center is the common position of those balls. 

Your task is to find the minimum number of operations to move all balls to the same position, or report that this is impossible.

Input

The first line contains a single integer t (1 ≤ t ≤ 100) — the number of test cases.

The first line of each test case contains two integers n, k (2 ≤ n ≤ 100, 0 ≤ k ≤ 10^6) — the number of balls and the attract power of all balls, respectively.

The following n lines describe the balls' coordinates. The i-th of these lines contains two integers x_i, y_i (0 ≤ x_i, y_i ≤ 10^5) — the coordinates of the i-th ball.

It is guaranteed that all points are distinct.

Output

For each test case print a single integer — the minimum number of operations to move all balls to the same position, or -1 if it is impossible.

Example

Input


3
3 2
0 0
3 3
1 1
3 3
6 7
8 8
6 9
4 1
0 0
0 1
0 2
0 3


Output


-1
1
-1

Note

In the first test case, there are three balls at (0, 0), (3, 3), and (1, 1) and the attract power is 2. It is possible to move two balls together with one operation, but not all three balls together with any number of operations.

In the second test case, there are three balls at (6, 7), (8, 8), and (6, 9) and the attract power is 3. If we charge any ball, the other two will move to the same position, so we only require one operation.

In the third test case, there are four balls at (0, 0), (0, 1), (0, 2), and (0, 3), and the attract power is 1. We can show that it is impossible to move all balls to the same position with a sequence of operations.
import java.util.*;
import java.util.Map.Entry;


import java.io.*;
import java.math.*;
import static java.util.stream.Collectors.*;
import static java.util.Map.Entry.*;

/* Name of the class has to be "Main" only if the class is public. */
public class Main
{
	
	public static void main (String[] args) throws IOException
	{
		final long mod=(long) (1e9+7);  
		Reader s=new Reader();
		  PrintWriter pt=new PrintWriter(System.out);
//		  BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		  int T=s.nextInt();
//		  int T=Integer.parseInt(br.readLine());
//		  int T=1;
		  while(T-->0)
		  {
			  int n=s.nextInt();
			  int k=s.nextInt();
			  int x[]=new int[n];
			  int y[]=new int[n];
			  for(int i=0;i<n;i++) {
				  x[i]=s.nextInt();
				  y[i]=s.nextInt();
			  }
			  int score[]=new int[n];
			  for(int i=0;i<n;i++) {
				  for(int j=0;j<n;j++) {
					  if(Math.abs(x[i]-x[j])+Math.abs(y[i]-y[j])<=k) {
						  score[i]++;
					  }
				  }
			  }
			  boolean flag = false;
			  for(int i=0;i<n;i++) {
				  if(score[i]==n)
					  flag=true;
			  }
			  if(flag)
				  pt.println(1);
			  else
				  pt.println(-1);
		  }
		  pt.close();
	}
	static boolean isSorted(int arr[], int n) {
		for(int i=1;i<n;i++) {
			if(arr[i]>=arr[i-1]==false) {
				return false;
			}
		}
		return true;
	}
	
	static int setBit(int S, int j) { return S | 1 << j; }

	static int clearBit(int S, int j) { return S & ~(1 << j); }

	static int toggleBit(int S, int j) { return S ^ 1 << j; }

	static boolean isOn(int S, int j) { return (S & 1 << j) != 0; }

	static int turnOnLastZero(int S) { return S | S + 1; }
	
	static int turnOnLastConsecutiveZeroes(int S) { return S | S - 1; }
	
	static int turnOffLastBit(int S) { return S & S - 1; }
	
	static int turnOffLastConsecutiveBits(int S) { return S & S + 1; }

	static int lowBit(int S) { return S & -S; }

	static int setAll(int N) { return (1 << N) - 1; }

	static int modulo(int S, int N) { return (S & N - 1); }		 //S%N, N is a power of 2

	static boolean isPowerOfTwo(int S) { return (S & S - 1) == 0; }
	
	static boolean isWithin(long x, long y, long d, long k) {
		return x*k*x*k + y*k*y*k <= d*d;
	}
	
	static long modFact(long n, 
            long p) 
	{ 
		if (n >= p) 
		 return 0; 
		
		long result = 1; 
		for (int i = 1; i <= n; i++) 
		 result = (result * i) % p; 
		
		return result; 
	} 
	static int sum(int[] arr, int n)
	{
	    int inc[]=new int[n+1];
	    int dec[]=new int[n+1];
	    inc[0] = arr[0];
	    dec[0] = arr[0];

	    for (int i = 1; i < n; i++) {
	        for (int j = 0; j < i; j++) {
	            if (arr[j] > arr[i]) {
	                dec[i] = max(dec[i], inc[j] + arr[i]);
	            }
	            else if (arr[i] > arr[j]) {
	                inc[i] = max(inc[i], dec[j] + arr[i]);
	            }
	        }
	    }
	    return max(inc[n - 1], dec[n - 1]);
	}
	static long nc2(long a) {
		return a*(a-1)/2;
	}
	public static int numberOfprimeFactors(int n) 
    { 
        // Print the number of 2s that divide n 
		HashSet<Integer> hs = new HashSet<Integer>();
        while (n%2==0) 
        { 
            hs.add(2);
            n /= 2; 
        } 
  
        // n must be odd at this point.  So we can 
        // skip one element (Note i = i +2) 
        for (int i = 3; i <= Math.sqrt(n); i+= 2) 
        { 
            // While i divides n, print i and divide n 
            while (n%i == 0) 
            { 
                hs.add(i);
                n /= i; 
            } 
        } 
  
        // This condition is to handle the case whien 
        // n is a prime number greater than 2 
        if (n > 2) 
            hs.add(n);
        return hs.size();
    } 
	static int gcd(int a, int b) 
    { 
      if (b == 0) 
        return a; 
      return gcd(b, a % b);  
    } 




	

	static void reverse(int arr[],int start, int end) 
	{ 
		int temp; 
		   
		while (start < end) 
		{ 
		    temp = arr[start];  
		    arr[start] = arr[end]; 
		    arr[end] = temp; 
		    start++; 
		    end--; 
		}  
	}  
	static void reverse(long arr[],int start, int end) 
	{ 
		long temp; 
		   
		while (start < end) 
		{ 
		    temp = arr[start];  
		    arr[start] = arr[end]; 
		    arr[end] = temp; 
		    start++; 
		    end--; 
		}  
	}  
	static boolean isPrime(int n) 
    { 
        // Corner cases 
        if (n <= 1) return false; 
        if (n <= 3) return true; 
      
        // This is checked so that we can skip  
        // middle five numbers in below loop 
        if (n % 2 == 0 || n % 3 == 0) return false; 
      
        for (int i = 5; i * i <= n; i = i + 6) 
            if (n % i == 0 || n % (i + 2) == 0) 
            return false; 
      
        return true; 
    } 
	static int p2(int n) {
		int k=0;
		while(n>1) {
			if(n%2!=0)
				return k;
			n/=2;
			k++;
		}
		return k;
	}
	static boolean isp2(int n) {
		while(n>1) {
			if(n%2==1)
				return false;
			n/=2;
		}
		return true;
	}
	static int binarySearch(int arr[], int first, int last, int key){  
		   int mid = (first + last)/2;  
		   while( first <= last ){  
		      if ( arr[mid] < key ){  
		        first = mid + 1;     
		      }else if ( arr[mid] == key ){  
		        return mid;  
		      }else{  
		         last = mid - 1;  
		      }  
		      mid = (first + last)/2;  
		   }  
		   return -1;
		 }  

	static void print(int a[][]) {
		for(int i=0;i<a.length;i++)
		{
			for(int j=0;j<a[0].length;j++)
				System.out.print(a[i][j]+" ");
			System.out.println();
		}
	}
	static int max (int x, int y) {
		return (x > y)? x : y;
	} 
	static int search(Pair[] p, Pair pair) {
		int l=0, r=p.length;
		while (l <= r) { 
	        int m = l + (r - l) / 2;
	        if (p[m].compareTo(pair)==0) 
	            return m; 
	        if (p[m].compareTo(pair)<0) 
	            l = m + 1; 
	        else
	            r = m - 1;
	    }
	    return -1;
	}
	static void pa(int a[])
	{
		for(int i=0;i<a.length;i++)
			System.out.print(a[i]+" ");
		System.out.println();
		
	}
	static void pa(long a[])
	{
		for(int i=0;i<a.length;i++)
			System.out.print(a[i]+" ");
		System.out.println();
		
	}
	static void reverseArray(int arr[], 
            int start, int end) 
	{ 
		int temp; 
		   
		while (start < end) 
		{ 
		    temp = arr[start];  
		    arr[start] = arr[end]; 
		    arr[end] = temp; 
		    start++; 
		    end--; 
		}  
	}     
	static boolean isPalindrome(String s) {
		int l=s.length();
		for(int i=0;i<l/2;i++)
		{
			if(s.charAt(i)!=s.charAt(l-i-1))
				return false;
		}
		return true;
	}
	static long nc2(long n, long m) {
		return (n*(n-1)/2)%m;
	}
	static long c(long a) {
		return a*(a+1)/2;
	}
	static int next(int[] arr, int target)  
    {  
        int start = 0, end = arr.length - 1;  
    
        int ans = -1;  
        while (start <= end) {  
            int mid = (start + end) / 2;  
    
            // Move to right side if target is  
            // greater.  
            if (arr[mid] < target) {  
                start = mid + 1;  
            }  
    
            // Move left side.  
            else {  
                ans = mid;  
                end = mid - 1;  
            }  
        }  
        return ans;  
    }  

	static long power(long x, long y, long p) 
    { 
        long res = 1; 
        x = x % p; 
                      
        while (y > 0) 
        { 
            if (y % 2 == 1) 
                res = (res * x) % p; 
            y = y >> 1;
            x = (x * x) % p; 
        } 
        return  res; 
    } 
    static long modInverse(long n, long p) 
    { 
        return power(n, p-2, p); 
    } 
    static long nCrModP(long n, long r, 
                                    long p) 
    { 
        if(r>n)
        	return 0;
    	if (r == 0) 
            return 1; 
        long[] fac = new long[(int) (n+1)]; 
        fac[0] = 1; 
        for (int i = 1 ;i <= n; i++) 
            fac[i] = fac[i-1] * i % p; 
        return (fac[(int) n]* modInverse(fac[(int) r], p) 
                % p * modInverse(fac[(int) (n-r)], p) 
                                    % p) % p; 
    } 
	static String reverse(String str)
	{
		return new StringBuffer(str).reverse().toString();
	}



	static long fastpow(long x, long y, long m)  
    { 
        if (y == 0) 
            return 1; 
          
        long p = fastpow(x, y / 2, m) % m; 
        p = (p * p) % m; 
      
        if (y % 2 == 0) 
            return p; 
        else
            return (x * p) % m; 
    } 
	
	static boolean isPerfectSquare(long l)
	{
		return Math.pow((long)Math.sqrt(l),2)==l;
	}
	
	
	static void merge(long[] arr, int l, int m, int r) 
    { 
        // Find sizes of two subarrays to be merged 
        int n1 = m - l + 1; 
        int n2 = r - m; 
  
        /* Create temp arrays */
        long L[] = new long [n1]; 
        long R[] = new long [n2]; 
  
        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i) 
            L[i] = arr[l + i]; 
        for (int j=0; j<n2; ++j) 
            R[j] = arr[m + 1+ j]; 
  
  
        /* Merge the temp arrays */
  
        // Initial indexes of first and second subarrays 
        int i = 0, j = 0; 
  
        // Initial index of merged subarry array 
        int k = l; 
        while (i < n1 && j < n2) 
        { 
            if (L[i] <= R[j]) 
            { 
                arr[k] = L[i]; 
                i++; 
            } 
            else
            { 
                arr[k] = R[j]; 
                j++; 
            } 
            k++; 
        } 
  
        /* Copy remaining elements of L[] if any */
        while (i < n1) 
        { 
            arr[k] = L[i]; 
            i++; 
            k++; 
        } 
  
        /* Copy remaining elements of R[] if any */
        while (j < n2) 
        { 
            arr[k] = R[j]; 
            j++; 
            k++; 
        } 
    } 
  
    // Main function that sorts arr[l..r] using 
    // merge() 
    static void sort(int arr[], int l, int r) 
    { 
        if (l < r) 
        { 
            // Find the middle point 
            int m = (l+r)/2; 
  
            // Sort first and second halves 
            sort(arr, l, m); 
            sort(arr , m+1, r); 
  
            // Merge the sorted halves 
            merge(arr, l, m, r); 
        } 
    } 
	static void merge(int arr[], int l, int m, int r) 
    { 
        // Find sizes of two subarrays to be merged 
        int n1 = m - l + 1; 
        int n2 = r - m; 
  
        /* Create temp arrays */
        int L[] = new int [n1]; 
        int R[] = new int [n2]; 
  
        /*Copy data to temp arrays*/
        for (int i=0; i<n1; ++i) 
            L[i] = arr[l + i]; 
        for (int j=0; j<n2; ++j) 
            R[j] = arr[m + 1+ j]; 
  
  
        /* Merge the temp arrays */
  
        // Initial indexes of first and second subarrays 
        int i = 0, j = 0; 
  
        // Initial index of merged subarry array 
        int k = l; 
        while (i < n1 && j < n2) 
        { 
            if (L[i] <= R[j]) 
            { 
                arr[k] = L[i]; 
                i++; 
            } 
            else
            { 
                arr[k] = R[j]; 
                j++; 
            } 
            k++; 
        } 
  
        /* Copy remaining elements of L[] if any */
        while (i < n1) 
        { 
            arr[k] = L[i]; 
            i++; 
            k++; 
        } 
  
        /* Copy remaining elements of R[] if any */
        while (j < n2) 
        { 
            arr[k] = R[j]; 
            j++; 
            k++; 
        } 
    } 
  
    // Main function that sorts arr[l..r] using 
    // merge() 
    static void sort(long arr[], int l, int r) 
    { 
        if (l < r) 
        { 
            // Find the middle point 
            int m = (l+r)/2; 
  
            // Sort first and second halves 
            sort(arr, l, m); 
            sort(arr , m+1, r); 
  
            // Merge the sorted halves 
            merge(arr, l, m, r); 
        } 
    } 
    static class Pair implements Comparable<Pair>{
        int a;
        int b;
        Pair(int a,int b){
            this.a=a;
 
            this.b=b;
        }   
        public int compareTo(Pair p){
            if(a>p.a)
                return 1;
            if(a==p.a)
                return (b-p.b);
            return -1;
        }
    }
	static class Reader 
    { 
        final private int BUFFER_SIZE = 1 << 16; 
        private DataInputStream din; 
        private byte[] buffer; 
        private int bufferPointer, bytesRead; 
  
        public Reader() 
        { 
            din = new DataInputStream(System.in); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public Reader(String file_name) throws IOException 
        { 
            din = new DataInputStream(new FileInputStream(file_name)); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public String readLine() throws IOException 
        { 
            byte[] buf = new byte[128]; // line length 
            int cnt = 0, c; 
            while ((c = read()) != -1) 
            { 
                if (c == '\n') 
                    break; 
                buf[cnt++] = (byte) c; 
            } 
            return new String(buf, 0, cnt); 
        } 
  
        public int nextInt() throws IOException 
        { 
            int ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do
            { 
                ret = ret * 10 + c - '0'; 
            }  while ((c = read()) >= '0' && c <= '9'); 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public long nextLong() throws IOException 
        { 
            long ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public double nextDouble() throws IOException 
        { 
            double ret = 0, div = 1; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
  
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
  
            if (c == '.') 
            { 
                while ((c = read()) >= '0' && c <= '9') 
                { 
                    ret += (c - '0') / (div *= 10); 
                } 
            } 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        private void fillBuffer() throws IOException 
        { 
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
            if (bytesRead == -1) 
                buffer[0] = -1; 
        } 
  
        private byte read() throws IOException 
        { 
            if (bufferPointer == bytesRead) 
                fillBuffer(); 
            return buffer[bufferPointer++]; 
        } 
  
        public void close() throws IOException 
        { 
            if (din == null) 
                return; 
            din.close(); 
        } 
    } 
}