using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Collections.Generic;
using System.Diagnostics;
using System.Numerics;
using Enu = System.Linq.Enumerable;

public class Program
{
    public void Solve()
    {
        int size = Reader.Int(), N = Reader.Int();
        var table = Reader.Range(N, () => Reader.IntTable(size));

        // →, ↓, ↘, ↗
        var SR = Enu.Range(0, size).Concat(new int[size]).Concat(new[] { 0, size - 1 }).ToArray();
        var SC = new int[size].Concat(Enu.Range(0, size)).Concat(new int[2]).ToArray();
        var DR = new int[size].Concat(Enu.Repeat(1, size)).Concat(new[] { 1, -1 }).ToArray();
        var DC = Enu.Repeat(1, size).Concat(new int[size]).Concat(new[] { 1, 1 }).ToArray();

        int ans = int.MaxValue;
        for (int who = 0; who < N; who++)
            for (int dir = 0; dir < SR.Length; dir++)
            {
                var set = new HashSet<int>();
                for (int i = 0, r = SR[dir], c = SC[dir]; i < size; i++, r += DR[dir], c += DC[dir])
                    set.Add(table[who][r][c]);

                for (int other = 0; other < N; other++)
                    if (who != other)
                        for (int dir2 = 0; dir2 < SR.Length; dir2++)
                        {
                            int count = 0;
                            for (int i = 0, r = SR[dir2], c = SC[dir2]; i < size; i++, r += DR[dir2], c += DC[dir2])
                                if (!set.Contains(table[other][r][c]))
                                    count++;
                            ans = Math.Min(ans, size + count - 1);
                        }

            }

        Console.WriteLine(ans);
    }
}


class Entry { static void Main() { new Program().Solve(); } }
class Reader
{
    static TextReader reader = Console.In;
    static readonly char[] separator = { ' ' };
    static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries;
    static string[] A = new string[0];
    static int i;
    static void Init() { A = new string[0]; }
    public static void Set(TextReader r) { reader = r; Init(); }
    public static void Set(string file) { reader = new StreamReader(file); Init(); }
    public static bool HasNext() { return CheckNext(); }
    public static string String() { return Next(); }
    public static int Int() { return int.Parse(Next()); }
    public static long Long() { return long.Parse(Next()); }
    public static double Double() { return double.Parse(Next()); }
    public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); }
    public static int[] IntArray(int N) { return Range(N, Int); }
    public static int[][] IntTable(int H) { return Range(H, IntLine); }
    public static string[] StringArray(int N) { return Range(N, Next); }
    public static string[][] StringTable(int N) { return Range(N, () => Split(Line())); }
    public static string Line() { return reader.ReadLine().Trim(); }
    public static T[] Range<T>(int N, Func<T> f) { var r = new T[N]; for (int i = 0; i < N; r[i++] = f()) ; return r; }
    static string[] Split(string s) { return s.Split(separator, op); }
    static string Next() { CheckNext(); return A[i++]; }
    static bool CheckNext()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return CheckNext();
        A = Split(line);
        i = 0;
        return true;
    }
}