using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        var map = NArr(n * m);
        var pos = new int[n, m];
        for (var i = 0; i < map.Length; ++i) pos[map[i][0] - 1, map[i][1] - 1] = i + 1;
        var ans = int.MaxValue;
        for (var i = 0; i + 4 <= n; ++i) for (var j = 0; j < m; ++j)
        {
            var p = new int[] { pos[i, j], pos[(i + 1) % n, j], pos[(i + 2) % n, j], pos[(i + 3) % n, j], pos[(i + 4) % n, j] };
            Array.Sort(p);
            ans = Math.Min(ans, Draw(p));
        }
        WriteLine(ans - 1);
    }
    static int Draw(int[] p)
    {
        var i = 0;
        var ans = 0;
        var draw = 0;
        while (i < p.Length)
        {
            var ntime = (p[i] - draw + p.Length - i - 1) / (p.Length - i);
            ans += ntime;
            draw += ntime * (p.Length - i);
            while(i < p.Length && p[i] <= draw) ++i;
        }
        return ans;
    }
}