Problem:
Score : 800 points

Problem Statement

Niwango-kun, an employee of Dwango Co., Ltd., likes Niconico TV-chan, so he collected a lot of soft toys of her and spread them on the floor.

Niwango-kun has N black rare soft toys of Niconico TV-chan and they are spread together with ordinary ones. He wanted these black rare soft toys to be close together, so he decided to rearrange them.

In an infinitely large two-dimensional plane, every lattice point has a soft toy on it. The coordinates (x_i,y_i) of N black rare soft toys are given. All soft toys are considered to be points (without a length, area, or volume).

He may perform the following operation arbitrarily many times:

Put an axis-aligned square with side length D, rotate the square by 90 degrees with four soft toys on the four corners of the square. More specifically, if the left bottom corner's coordinate is (x, y), rotate four points (x,y) \rightarrow (x+D,y) \rightarrow (x+D,y+D) \rightarrow (x,y+D) \rightarrow (x,y) in this order. Each of the four corners of the square must be on a lattice point.

Let's define the scatteredness of an arrangement by the minimum side length of an axis-aligned square enclosing all black rare soft toys. Black rare soft toys on the edges or the vertices of a square are considered to be enclosed by the square.

Find the minimum scatteredness after he performs arbitrarily many operations.

Constraints

2 \leq N \leq 10^5

1 \leq D \leq 1000

0 \leq x_i, y_i \leq 10^9

Given coordinates are pairwise distinct

All numbers given in input are integers

Partial Scores

500 points will be awarded for passing the test set satisfying 1 \leq D \leq 30.

Input

Input is given from Standard Input in the following format:

N D
x_1 y_1
:
x_N y_N

Output

Print the answer.

Sample Input 1

3 1
0 0
1 0
2 0

Sample Output 1

1

Sample Input 2

19 2
1 3
2 3
0 1
1 1
2 1
3 1
4 4
5 4
6 4
7 4
8 4
8 3
8 2
8 1
8 0
7 0
6 0
5 0
4 0

Sample Output 2

4

Sample Input 3

8 3
0 0
0 3
3 0
3 3
2 2
2 5
5 2
5 5

Sample Output 3

4

Solution in C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;

public class Solver
{
    public void Solve()
    {
        int n = ReadInt();
        int d = ReadInt();

        if (d > 30)
            throw new Exception();

        var a = new int[d, d];
        for (int i = 0; i < n; i++)
        {
            int x = ReadInt();
            int y = ReadInt();
            a[x % d, y % d]++;
        }

        var szx = new int[n + 1];
        var szy = new int[n + 1];
        int p = 1, rr = 0, rt = 0;
        for (int i = 2; i <= n; i++)
        {
            szx[i] = szx[i - 1];
            szy[i] = szy[i - 1];
            if (rr == 0)
            {
                if (rt == 0)
                {
                    p++;
                    rr = p - 1;
                    rt = p;

                    szx[i]++;
                    rr--;
                }
                else
                {
                    if (rt == p)
                        szy[i]++;
                    rt--;
                }
            }
            else
                rr--;
        }

        int ans = int.MaxValue;
        for (int dx = 0; dx < d; dx++)
            for (int dy = 0; dy < d; dy++)
            {
                int mx = 0, my = 0;
                for (int i = 0; i < d; i++)
                    for (int j = 0; j < d; j++)
                        if (a[i, j] > 0)
                        {
                            int sx, sy;
                            int px = i;
                            int py = j;
                            if (i < dx)
                                px += d;
                            if (j < dy)
                                py += d;
                            if (px < py)
                            {
                                sx = szx[a[i, j]] * d + px;
                                sy = szy[a[i, j]] * d + py;
                            }
                            else
                            {
                                sx = szy[a[i, j]] * d + px;
                                sy = szx[a[i, j]] * d + py;
                            }
                            mx = Math.Max(mx, sx);
                            my = Math.Max(my, sy);
                        }
                ans = Math.Min(ans, Math.Max(mx - dx, my - dy));
            }

        Write(ans);
    }

    #region Main

    protected static TextReader reader;
    protected static TextWriter writer;
    static void Main()
    {
#if DEBUG
        reader = new StreamReader("..\\..\\input.txt");
        //reader = new StreamReader(Console.OpenStandardInput());
        writer = Console.Out;
        //writer = new StreamWriter("..\\..\\output.txt");
#else
        reader = new StreamReader(Console.OpenStandardInput());
        writer = new StreamWriter(Console.OpenStandardOutput());
        //reader = new StreamReader("input.txt");
        //writer = new StreamWriter("output.txt");
#endif
        try
        {
            new Solver().Solve();
            //var thread = new Thread(new Solver().Solve, 1024 * 1024 * 128);
            //thread.Start();
            //thread.Join();
        }
        catch (Exception ex)
        {
#if DEBUG
            Console.WriteLine(ex);
#else
            throw;
#endif
        }
        reader.Close();
        writer.Close();
    }

    #endregion

    #region Read / Write
    private static Queue<string> currentLineTokens = new Queue<string>();
    private static string[] ReadAndSplitLine() { return reader.ReadLine().Split(new[] { ' ', '\t', }, StringSplitOptions.RemoveEmptyEntries); }
    public static string ReadToken() { while (currentLineTokens.Count == 0)currentLineTokens = new Queue<string>(ReadAndSplitLine()); return currentLineTokens.Dequeue(); }
    public static int ReadInt() { return int.Parse(ReadToken()); }
    public static long ReadLong() { return long.Parse(ReadToken()); }
    public static double ReadDouble() { return double.Parse(ReadToken(), CultureInfo.InvariantCulture); }
    public static int[] ReadIntArray() { return ReadAndSplitLine().Select(int.Parse).ToArray(); }
    public static long[] ReadLongArray() { return ReadAndSplitLine().Select(long.Parse).ToArray(); }
    public static double[] ReadDoubleArray() { return ReadAndSplitLine().Select(s => double.Parse(s, CultureInfo.InvariantCulture)).ToArray(); }
    public static int[][] ReadIntMatrix(int numberOfRows) { int[][] matrix = new int[numberOfRows][]; for (int i = 0; i < numberOfRows; i++)matrix[i] = ReadIntArray(); return matrix; }
    public static int[][] ReadAndTransposeIntMatrix(int numberOfRows)
    {
        int[][] matrix = ReadIntMatrix(numberOfRows); int[][] ret = new int[matrix[0].Length][];
        for (int i = 0; i < ret.Length; i++) { ret[i] = new int[numberOfRows]; for (int j = 0; j < numberOfRows; j++)ret[i][j] = matrix[j][i]; } return ret;
    }
    public static string[] ReadLines(int quantity) { string[] lines = new string[quantity]; for (int i = 0; i < quantity; i++)lines[i] = reader.ReadLine().Trim(); return lines; }
    public static void WriteArray<T>(IEnumerable<T> array) { writer.WriteLine(string.Join(" ", array)); }
    public static void Write(params object[] array) { WriteArray(array); }
    public static void WriteLines<T>(IEnumerable<T> array) { foreach (var a in array)writer.WriteLine(a); }
    private class SDictionary<TKey, TValue> : Dictionary<TKey, TValue>
    {
        public new TValue this[TKey key]
        {
            get { return ContainsKey(key) ? base[key] : default(TValue); }
            set { base[key] = value; }
        }
    }
    private static T[] Init<T>(int size) where T : new() { var ret = new T[size]; for (int i = 0; i < size; i++)ret[i] = new T(); return ret; }
    #endregion
}