#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))

// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;

int n,m;
vector< vector<vi> > C;

int main(){
  scanf("%d%d",&n,&m);
  C.resize(m);
  REP(i,m){
    C[i].resize(n);
    REP(j,n){
      C[i][j].resize(n);
      REP(k,n)scanf("%d",&C[i][j][k]);
    }
  }
  vector< vector<vi> > U;
  U.resize(m);
  REP(i,m){
    // tate,yoko
    REP(j,n){
      vi x;
      vi y;
      REP(k,n){
        x.push_back(C[i][j][k]);
        y.push_back(C[i][k][j]);
      }
      sort(ALL(x));
      sort(ALL(y));
      U[i].push_back(x);
      U[i].push_back(y);
    }
    // naname
    {
      vi x;
      vi y;
      REP(k,n){
        x.push_back(C[i][k][k]);
        y.push_back(C[i][k][n-1-k]);
      }
      sort(ALL(x));
      sort(ALL(y));
      U[i].push_back(x);
      U[i].push_back(y);
    }
  }
  // all check
  {
    set<vi> S;
    REP(i,m){
      for(vi V:U[i]){
        if(S.count(V)){
          printf("%d\n",n-1);
          return 0;
        }
      }
      for(vi V:U[i]){
        S.insert(V);
      }
    }
  }
  // partial check
  int ans = 252521;
  REP(i,m){
    for(vi V:U[i]){
      REP(j,m){
        if(i==j)continue;
        for(vi W:U[j]){
          // same count
          int same = 0;
          int x=0, y=0;
          while(x<n && y<n){
            if(V[x]==W[y]){
              same++;
              x++;
              y++;
            }else if(V[x]<W[y]){
              x++;
            }else{
              y++;
            }
          }
          CHMIN(ans,n+(n-same-1));
        }
      }
    }
  }
  printf("%d\n",ans);
  return 0;
}