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.io.*;
import java.util.*;
import static java.lang.Math.*;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class AvoidTrygub {
    public static void main(String[] args) throws IOException {
        // InputStream inputStream = new FileInputStream("input.txt");
        // OutputStream outputStream = new FileOutputStream("output.txt");
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(in.nextInt(), in, out);
        out.close();
    }
    static class TaskA {
        long mod = (long)(1e9) + 7;
        long fact[];
        int depth[];
        int parentTable[][];
        int degree[];
        ArrayList<Integer> leaves;
        int max = Integer.MIN_VALUE;
        int min = Integer.MAX_VALUE;
        int diam = 0;

        int res = 0;

        public void solve(int testNumber, InputReader in, PrintWriter out) throws IOException {
            while(testNumber-->0){
                int n = in.nextInt();
                int k = in.nextInt();
                int a[][] = new int[n][n];
                for(int i=0;i<n;i++){
                    int x = in.nextInt();
                    int y = in.nextInt();
                    a[i] = new int[]{x , y};
                }
                int ans = -1;
                for(int i=0;i<n;i++){
                    int count = 0;
                    for(int j=0;j<n;j++){
                        if(abs(a[i][0]-a[j][0]) + abs(a[i][1] - a[j][1]) <= k)
                            count++;
                    }
                    if(count == n)
                        ans = 1;
                }
                out.println(ans);
            }
        }

        class Sort implements Comparator<int[]>{
        	public int compare(int a[] , int b[]){
        		return a[0]+a[1] - b[0] - b[1];
        	}
        }

        public int lower(ArrayList<Integer> a , int x){
            if(a.size() == 0)
                return 0;
            if(a.get(a.size()-1) < x)
                return a.size();
            int l = 0;
            int r = a.size()-1;
            while(l<=r){
                int mid = (l+r)>>1;
                if(a.get(mid)>=x && (mid<1 || a.get(mid-1)<x))
                    return mid;
                else if(a.get(mid) < x)
                    l = mid+1;
                else
                    r = mid-1;
            }
            return -1;
        }

        public int distance(ArrayList<ArrayList<Integer>> a , int u , int v){
            return depth[u]+depth[v] - 2*depth[lca(a , u , v)];
        }

        public int lca(ArrayList<ArrayList<Integer>> a , int u , int v){
            if(depth[v]<depth[u]){
                int x = u;
                u = v;
                v = x;
            }
            int diff = depth[v] - depth[u];
            for(int i=0;i<parentTable[v].length;i++){
                // checking whether the ith bit is set in the diff variable
                if(((diff>>i)&1) == 1)
                    v = parentTable[v][i];
            }
            if(v == u)
                return v;
            for(int i=parentTable[v].length-1;i>=0;i--){
                if(parentTable[u][i] != parentTable[v][i]){
                    v = parentTable[v][i];
                    u = parentTable[u][i];
                }
            }
            return parentTable[u][0];
        }
        

        public int[][] multiply(int a[][] , int b[][]){
            int c[][] = new int[a.length][b[0].length];
            for(int i=0;i<a.length;i++){
                for(int j=0;j<b[0].length;j++){
                    for(int k=0;k<b.length;k++)
                        c[i][j] += a[i][k]*b[k][j];
                }
            }
            return c;
        }

        public int[][] multiply(int a[][] , int b[][] , int mod){
            int c[][] = new int[a.length][b[0].length];
            for(int i=0;i<a.length;i++){
                for(int j=0;j<b[0].length;j++){
                    for(int k=0;k<b.length;k++){
                        c[i][j] += a[i][k]*b[k][j];
                        c[i][j]%=mod;
                    }
                }
            }
            return c;
        }

        public int[][] pow(int a[][] , long b){
            int res[][] = new int[a.length][a[0].length];
            for(int i=0;i<a.length;i++)
                res[i][i] = 1;
            while(b>0){
                if((b&1) == 1)
                    res = multiply(res , a , 10);
                a = multiply(a , a , 10);
                b>>=1;
            }
            return res;
        }

        

        // for the min max problems
        public void build(int lookup[][] , int arr[], int n) { 
            for (int i = 0; i < n; i++) 
                lookup[i][0] = arr[i]; 
            for (int j = 1; (1 << j) <= n; j++) { 
                for (int i = 0; (i + (1 << j) - 1) < n; i++) { 
                    if (lookup[i][j - 1] > lookup[i + (1 << (j - 1))][j - 1]) 
                        lookup[i][j] = lookup[i][j - 1]; 
                    else
                        lookup[i][j] = lookup[i + (1 << (j - 1))][j - 1]; 
                } 
            } 
        }
        public int query(int lookup[][] , int L, int R) { 
            int j = (int)(Math.log(R - L + 1)/Math.log(2)); 
            if (lookup[L][j] >= lookup[R - (1 << j) + 1][j]) 
                return lookup[L][j]; 
            else
                return lookup[R - (1 << j) + 1][j]; 
        }

        // for printing purposes
        public void print1d(int a[] , PrintWriter out){
            for(int i=0;i<a.length;i++)
                out.print(a[i] + " ");
            out.println();
        }
        public void print1d(long a[] , PrintWriter out){
            for(int i=0;i<a.length;i++)
                out.print(a[i] + " ");
            out.println();
        }
        public void print2d(int a[][] , PrintWriter out){
            for(int i=0;i<a.length;i++){
                for(int j=0;j<a[i].length;j++)
                    out.print(a[i][j] + " ");
                out.println();
            }
            // out.println();
        }
        public void print2d(long a[][] , PrintWriter out){
            for(int i=0;i<a.length;i++){
                for(int j=0;j<a[i].length;j++)
                    out.print(a[i][j] + " ");
                out.println();
            }
            // out.println();
        }


        public void sieve(int a[]){
            a[0] = a[1] = 1;
            int i;
            for(i=2;i*i<=a.length;i++){
                if(a[i] != 0)
                    continue;
                a[i] = i;
                for(int k = (i)*(i);k<a.length;k+=i){
                    if(a[k] != 0)
                        continue;
                    a[k] = i;
                }
            }
        }

        public long nCrPFermet(int n , int r , long p){
            if(r==0)
                return 1l;
            // long fact[] = new long[n+1];
            // fact[0] = 1;
            // for(int i=1;i<=n;i++)
            //     fact[i] = (i*fact[i-1])%p;
            long modInverseR = pow(fact[r] , p-2 , p);
            long modInverseNR = pow(fact[n-r] , p-2 , p);
            long w = (((fact[n]*modInverseR)%p)*modInverseNR)%p;
            return w;
        }
        public long pow(long a, long b, long m) {
            a %= m;
            long res = 1;
            while (b > 0) {
                long x = b&1;
                if (x == 1)
                    res = res * a % m;
                a = a * a % m;
                b >>= 1;
            }
            return res;
        }
        public long pow(long a, long b) {
            long res = 1;
            while (b > 0) {
                long x = b&1;
                if (x == 1)
                    res = res * a;
                a = a * a;
                b >>= 1;
            }
            return res;
        }
        public void sortedArrayToBST(TreeSet<Integer> a , int start, int end) { 
            if (start > end) {
                return;
            }
            int mid = (start + end) / 2;
            a.add(mid);
            sortedArrayToBST(a, start, mid - 1);
            sortedArrayToBST(a, mid + 1, end); 
        }
        class Combine{
            int value;
            int delete;
            Combine(int val , int delete){
                this.value = val;
                this.delete = delete;
            }
        }
        class Sort2 implements Comparator<Combine>{
            public int compare(Combine a , Combine b){
                if(a.value > b.value)
                    return 1;
                else if(a.value == b.value && a.delete>b.delete)
                    return 1;
                else if(a.value == b.value && a.delete == b.delete)
                    return 0;
                return -1;
            }
        }
        public int lowerLastBound(ArrayList<Integer> a , int x){
            int l = 0;
            int r = a.size()-1;
            if(a.get(l)>=x)
                return -1;
            if(a.get(r)<x)
                return r;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a.get(mid) == x && a.get(mid-1)<x)
                    return mid-1;
                else if(a.get(mid)>=x)
                    r = mid-1;
                else if(a.get(mid)<x && a.get(mid+1)>=x)
                    return mid;
                else if(a.get(mid)<x && a.get(mid+1)<x)
                    l = mid+1;
            }
            return mid;
        }
        public int upperFirstBound(ArrayList<Integer> a , int x){
            int l = 0;
            int r = a.size()-1;
            if(a.get(l)>x)
                return l;
            if(a.get(r)<=x)
                return r+1;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a.get(mid) == x && a.get(mid+1)>x)
                    return mid+1;
                else if(a.get(mid)<=x)
                    l = mid+1;
                else if(a.get(mid)>x && a.get(mid-1)<=x)
                    return mid;
                else if(a.get(mid)>x && a.get(mid-1)>x)
                    r = mid-1;
            }
            return mid;
        }
        public int lowerLastBound(long a[] , long x){
            int l = 0;
            int r = a.length-1;
            if(a[l]>=x)
                return -1;
            if(a[r]<x)
                return r;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a[mid] == x && a[mid-1]<x)
                    return mid-1;
                else if(a[mid]>=x)
                    r = mid-1;
                else if(a[mid]<x && a[mid+1]>=x)
                    return mid;
                else if(a[mid]<x && a[mid+1]<x)
                    l = mid+1;
            }
            return mid;
        }
        public int upperFirstBound(long a[] , long x){
            int l = 0;
            int r = a.length-1;
            if(a[l]>x)
                return l;
            if(a[r]<=x)
                return r+1;
            int mid = -1;
            while(l<=r){
                mid = (l+r)/2;
                if(a[mid] == x && a[mid+1]>x)
                    return mid+1;
                else if(a[mid]<=x)
                    l = mid+1;
                else if(a[mid]>x && a[mid-1]<=x)
                    return mid;
                else if(a[mid]>x && a[mid-1]>x)
                    r = mid-1;
            }
            return mid;
        }
        public long log(float number , int base){
            return (long) Math.ceil((Math.log(number) / Math.log(base)) + 1e-9);
        }
        public long gcd(long a , long b){
            if(a<b){
                long c = b;
                b = a;
                a = c;
            }
            while(b!=0){
                long c = a;
                a = b;
                b = c%a;
            }
            return a;
        }
        public long[] gcdEx(long p, long q) {
            if (q == 0)
                return new long[] { p, 1, 0 };
            long[] vals = gcdEx(q, p % q);
            long d = vals[0];
            long a = vals[2];
            long b = vals[1] - (p / q) * vals[2];
            // 0->gcd 1->xValue 2->yValue
            return new long[] { d, a, b };
        }
        public void sievePhi(int a[]){
            a[0] = 0;
            a[1] = 1;
            for(int i=2;i<a.length;i++)
                a[i] = i-1;
            for(int i=2;i<a.length;i++)
                for(int j = 2*i;j<a.length;j+=i)
                    a[j] -= a[i];
        }
        public void lcmSum(long a[]){
            int sievePhi[] = new int[(int)1e6 + 1];
            sievePhi(sievePhi);
            a[0] = 0;
            for(int i=1;i<a.length;i++)
                for(int j = i;j<a.length;j+=i)
                    a[j] += (long)i*sievePhi[i];
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

    }
}