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.awt.Point;

public class Main {

	public static void main(final String[] args) {
		new Main();
	}

	public Main() {
		final FastScanner fs = new FastScanner();
		final java.io.PrintWriter out = new java.io.PrintWriter(System.out);
		solve(fs, out);
		out.flush();
	}

	public void solve(final FastScanner fs, final java.io.PrintWriter out) {
		int t = fs.nextInt();
		cont2: while(t --> 0) {
			final int n = fs.nextInt(), k = fs.nextInt();
			final Point[] p = new Point[n];
			for (int i = 0;i < n;++ i) p[i] = new Point(fs.nextInt(), fs.nextInt());
			cont: for (int i = 0;i < n;++ i) {
				for (int j = 0;j < n;++ j) {
					if (Math.abs(p[i].x - p[j].x) + Math.abs(p[i].y - p[j].y) > k) continue cont;
				}
				out.println(1);
				continue cont2;
			}
			out.println(-1);
		}
	}
}

class FastScanner {

	private final java.io.InputStream in = System.in;
	private final byte[] buffer = new byte[8192];
	private int ptr = 0;
	private int buflen = 0;

	private boolean hasNextByte() {
		if (ptr < buflen) return true;
		ptr = 0;
		try {
			buflen = in.read(buffer);
		} catch (final java.io.IOException e) {
			e.printStackTrace();
		}
		return buflen > 0;
	}

	private byte readByte() {
		return hasNextByte() ? buffer[ptr++ ] : -1;
	}

	private static boolean isPrintableChar(final byte c) {
		return 32 < c || c < 0;
	}

	private static boolean isNumber(final int c) {
		return '0' <= c && c <= '9';
	}

	public boolean hasNext() {
		while (hasNextByte() && !isPrintableChar(buffer[ptr]))
			ptr++ ;
		return hasNextByte();
	}

	public String next() {
		if (!hasNext()) throw new java.util.NoSuchElementException();
		final StringBuilder sb = new StringBuilder();
		byte b;
		while (isPrintableChar(b = readByte()))
			sb.appendCodePoint(b);
		return sb.toString();
	}

	public final char nextChar() {
		if (!hasNext()) throw new java.util.NoSuchElementException();
		return (char)readByte();
	}

	public final long nextLong() {
		if (!hasNext()) throw new java.util.NoSuchElementException();
		long n = 0;
		try {
			byte b = readByte();
			if (b == '-') {
				while (isNumber(b = readByte()))
					n = n * 10 + '0' - b;
				return n;
			} else if (!isNumber(b)) throw new NumberFormatException();
			do
				n = n * 10 + b - '0';
			while (isNumber(b = readByte()));
		} catch (final java.util.NoSuchElementException e) {}
		return n;
	}

	public final int nextInt() {
		if (!hasNext()) throw new java.util.NoSuchElementException();
		int n = 0;
		try {
			byte b = readByte();
			if (b == '-') {
				while (isNumber(b = readByte()))
					n = n * 10 + '0' - b;
				return n;
			} else if (!isNumber(b)) throw new NumberFormatException();
			do
				n = n * 10 + b - '0';
			while (isNumber(b = readByte()));
		} catch (final java.util.NoSuchElementException e) {}
		return n;
	}

	public double nextDouble() {
		return Double.parseDouble(next());
	}
}

class Arrays {

	public static void sort(final int[] array) {
		int l, min = 0xFFFFFFFF, max = 0;
		for (l = 0; l < array.length; ++l) {
			final int i = array[l];
			min &= i;
			max |= i;
			if ((i & 0x80000000) == 0) break;
		}
		for (int r = l + 1; r < array.length; ++r) {
			final int i = array[r];
			min &= i;
			max |= i;
			if ((i & 0x80000000) != 0) {
				array[r] = array[l];
				array[l++ ] = i;
			}
		}
		final int use = min ^ max, bit = Integer.highestOneBit(use & 0x7FFFFFFF);
		if (bit == 0) return;
		sort(array, 0, l, use, bit);
		sort(array, l, array.length, use, bit);
	}

	private static void sort(final int[] array, final int left, final int right, final int use, int digit) {
		if (right - left <= 96) {
			for (int i = left + 1; i < right; ++i) {
				final int tmp = array[i];
				int tmp2, j;
				for (j = i; j > left && (tmp2 = array[j - 1]) > tmp; --j)
					array[j] = tmp2;
				array[j] = tmp;
			}
			return;
		}
		int l = left;
		while (l < right && (array[l] & digit) == 0)
			++l;
		for (int r = l + 1; r < right; ++r) {
			final int i = array[r];
			if ((i & digit) == 0) {
				array[r] = array[l];
				array[l++ ] = i;
			}
		}
		if ((digit = Integer.highestOneBit(use & digit - 1)) == 0) return;
		sort(array, left, l, use, digit);
		sort(array, l, right, use, digit);
	}

	public static void sort(final long[] array) {
		int l;
		long min = 0xFFFFFFFFFFFFFFFFL, max = 0;
		for (l = 0; l < array.length; ++l) {
			final long i = array[l];
			min &= i;
			max |= i;
			if ((i & 0x8000000000000000L) == 0) break;
		}
		for (int r = l + 1; r < array.length; ++r) {
			final long i = array[r];
			min &= i;
			max |= i;
			if ((i & 0x8000000000000000L) != 0) {
				array[r] = array[l];
				array[l++ ] = i;
			}
		}
		final long use = min ^ max, bit = Long.highestOneBit(use & 0x7FFFFFFFFFFFFFFFL);
		if (bit == 0) return;
		sort(array, 0, l, use, bit);
		sort(array, l, array.length, use, bit);
	}

	private static void sort(final long[] array, final int left, final int right, final long use, long digit) {
		if (right - left <= 96) {
			for (int i = left + 1, j; i < right; ++i) {
				final long tmp = array[i];
				long tmp2;
				for (j = i; j > left && (tmp2 = array[j - 1]) > tmp; --j)
					array[j] = tmp2;
				array[j] = tmp;
			}
			return;
		}
		int l = left;
		while (l < right && (array[l] & digit) == 0)
			++l;
		for (int r = l + 1; r < right; ++r) {
			final long i = array[r];
			if ((i & digit) == 0) {
				array[r] = array[l];
				array[l++ ] = i;
			}
		}
		if ((digit = Long.highestOneBit(use & digit - 1)) == 0) return;
		sort(array, left, l, use, digit);
		sort(array, l, right, use, digit);
	}
}

class IntMath {

	public static int gcd(int a, int b) {
		while (a != 0)
			if ((b %= a) != 0) a %= b;
			else return a;
		return b;
	}

	public static int gcd(final int... array) {
		int ret = array[0];
		for (int i = 1; i < array.length; ++i)
			ret = gcd(ret, array[i]);
		return ret;
	}

	public static long gcd(long a, long b) {
		while (a != 0)
			if ((b %= a) != 0) a %= b;
			else return a;
		return b;
	}

	public static long gcd(final long... array) {
		long ret = array[0];
		for (int i = 1; i < array.length; ++i)
			ret = gcd(ret, array[i]);
		return ret;
	}

	public static long lcm(final long a, final long b) {
		return a / gcd(a, b) * b;
	}

	public static int pow(final int a, int b) {
		int ans = 1;
		for (int mul = a; b > 0; b >>= 1, mul *= mul)
			if ((b & 1) != 0) ans *= mul;
		return ans;
	}

	public static long powLong(final long a, long b) {
		long ans = 1;
		for (long mul = a; b > 0; b >>= 1, mul *= mul)
			if ((b & 1) != 0) ans *= mul;
		return ans;
	}

	public static int pow(final int a, int b, final int mod) {
		if (b < 0) b = b % (mod - 1) + mod - 1;
		long ans = 1;
		for (long mul = a; b > 0; b >>= 1, mul = mul * mul % mod)
			if ((b & 1) != 0) ans = ans * mul % mod;
		return (int)ans;
	}

	public static int floorsqrt(final long n) {
		return (int)Math.sqrt(n + 0.1);
	}

	public static int ceilsqrt(final long n) {
		return n <= 1 ? (int)n : (int)Math.sqrt(n - 0.1) + 1;
	}
}
