/* -*- coding: utf-8 -*-
 *
 * 452.cc: No.452 横着者のビンゴゲーム - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100;
const int MAX_K = MAX_N * 2 + 2;
const int MAX_M = 200;
const int INF = 1 << 30;

/* typedef */

typedef vector<int> vi;
typedef queue<int> qi;
typedef pair<int,int> pii;

/* global variables */

int cs[MAX_N][MAX_N];
int bs[MAX_M][MAX_K][MAX_N];

/* subroutines */

/* main */

int main() {
  int n, m;
  cin >> n >> m;
  int l = n * 2 + 2;

  for (int i = 0; i < m; i++) {
    for (int y = 0; y < n; y++)
      for (int x = 0; x < n; x++) cin >> cs[y][x];
    int j = 0;
    for (int y = 0; y < n; y++, j++)
      for (int x = 0; x < n; x++) bs[i][j][x] = cs[y][x];
    for (int x = 0; x < n; x++, j++)
      for (int y = 0; y < n; y++) bs[i][j][y] = cs[y][x];
    for (int y = 0; y < n; y++) bs[i][j][y] = cs[y][y];
    j++;
    for (int y = 0; y < n; y++) bs[i][j][y] = cs[y][n - 1 - y];

    for (int j = 0; j < l; j++) sort(bs[i][j], bs[i][j] + n);
  }

  int maxc = 0;
  for (int i0 = 0; i0 < m; i0++)
    for (int i1 = i0 + 1; i1 < m; i1++)
      for (int j0 = 0; j0 < l; j0++)
	for (int j1 = 0; j1 < l; j1++) {
	  int c = 0;
	  for (int k0 = 0; k0 < n; k0++) {
	    int k1 =
	      lower_bound(bs[i1][j1], bs[i1][j1] + n, bs[i0][j0][k0])
	      - bs[i1][j1];
	    if (k1 < n && bs[i1][j1][k1] == bs[i0][j0][k0]) c++;
	  }
	  if (maxc < c) maxc = c;
	}

  //printf("maxc=%d\n", maxc);
  printf("%d\n", n * 2 - maxc - 1);
  return 0;
}