#include <bits/stdc++.h>
#define EPS 1e-9
#define INF 1070000000LL
#define MOD 1000000007LL
#define fir first
#define foreach(it,X) for(auto it=(X).begin();it!=(X).end();it++)
#define numa(x,a) for(auto x: a)
#define ite iterator
#define mp make_pair
#define rep(i,n) rep2(i,0,n)
#define rep2(i,m,n) for(int i=m;i<(n);i++)
#define pb push_back
#define pf push_front
#define sec second
#define sz(x) ((int)(x).size())
#define ALL( c ) (c).begin(), (c).end()
#define gcd(a,b) __gcd(a,b)
#define mem(x,n) memset(x,n,sizeof(x))
#define endl "\n"
using namespace std;
template <int POS, class TUPLE> void deploy(std::ostream &os, const TUPLE &tuple){}
template <int POS, class TUPLE, class H, class ...Ts> void deploy(std::ostream &os, const TUPLE &t){ os << (POS == 0 ? "" : ", ") << get<POS>(t); deploy<POS + 1, TUPLE, Ts...>(os, t); }
template <class T,class U> std::ostream& operator<<(std::ostream &os, std::pair<T,U> &p){ os << "(" << p.first <<", " << p.second <<")";return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::vector<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T> std::ostream& operator<<(std::ostream &os, std::set<T> &v){ int remain = v.size(); os << "{"; for(auto e: v) os << e << (--remain == 0 ? "}" : ", "); return os; }
template <class T, class K> std::ostream& operator<<(std::ostream &os, std::map<T, K> &mp){ int remain = mp.size(); os << "{"; for(auto e: mp) os << "(" << e.first << " -> " << e.second << ")" << (--remain == 0 ? "}" : ", "); return os; }
#define DEBUG1(var0) { std::cerr << (#var0) << "=" << (var0) << endl; }
#define DEBUG2(var0, var1) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG1(var1); }
#define DEBUG3(var0, var1, var2) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG2(var1,var2); }
#define DEBUG4(var0, var1, var2, var3) { std::cerr << (#var0) << "=" << (var0) << ", ";DEBUG3(var1,var2,var3); }
using ll = long long;

vector <int> bd[210][210];
int calc(const vector <int> &A, const vector <int> &B){
  assert(sz(B) == sz(A));
  int N = sz(A);
  int cnt = 0;
  for (int i = 0, j = 0; i < N; i++) {
    while (j < N && A[i] > B[j]) {
      j++;
    }
    if (j < N && A[i] == B[j]) {
      cnt += 1;
    }
  }
  return max(1, 2 * N - cnt - 1);
}
int main()
{
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  int N, M; cin >> N >> M;
  rep(i,M){
    vector <int>r;
    vector <int>l;
    rep(j,N){
      rep(k,N){
        int x;
        cin >> x;
        bd[i][j].pb(x);
        bd[i][N+k].pb(x);
        if (j + k == N-1) {
          r.pb(x);
        }
        if (j == k) {
          l.pb(x);
        }
      }
    }
    bd[i][N*2] = move(r);
    bd[i][N*2+1] = move(l);
    rep(j,2*N+2){
      sort(ALL(bd[i][j]));
    }
  }
  int ans = INF;
  rep(i,M){
    rep(j,2*N+2){
      rep2(k,i+1,M){
        rep(l,2*N+2){
          ans = min(ans, calc(bd[i][j], bd[k][l]));
        }
      }
    }
  }
  cout << ans << endl;
  
  return 0;
}