#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <iomanip>
#include <cassert>
using namespace std;

#define GET_ARG(a,b,c,F,...) F
#define REP3(i,s,e) for (i = s; i <= e; i++)
#define REP2(i,n) REP3 (i,0,(int)(n)-1)
#define REP(...) GET_ARG (__VA_ARGS__,REP3,REP2) (__VA_ARGS__)
#define RREP3(i,s,e) for (i = s; i >= e; i--)
#define RREP2(i,n) RREP3 (i,(int)(n)-1,0)
#define RREP(...) GET_ARG (__VA_ARGS__,RREP3,RREP2) (__VA_ARGS__)
#define DEBUG(x) cerr << #x ": " << x << endl

int c[200][100][100];
vector<set<int>> nums[200];

int main(void) {
    int i, j, k, n, m;
    scanf("%d%d",&n,&m);
    REP (k,m) REP (i,n) REP (j,n) scanf("%d",&c[k][i][j]);

    REP (k,m) {
        REP (i,n) {
            set<int> st;
            REP (j,n) st.insert(c[k][i][j]);
            nums[k].push_back(st);
        }
        REP (j,n) {
            set<int> st;
            REP (i,n) st.insert(c[k][i][j]);
            nums[k].push_back(st);
        }
        {
            set<int> st;
            REP (i,n) st.insert(c[k][i][i]);
            nums[k].push_back(st);
        }
        {
            set<int> st;
            REP (i,n) st.insert(c[k][i][n-i-1]);
            nums[k].push_back(st);
        }
    }

    int a, b, ans = 1e8;
    REP (a,m) REP (b,m) if (a != b) {
        REP (i,n) {
            set<int> st;
            REP (j,n) st.insert(c[b][i][j]);
            for (auto s: nums[a]) {
                int same = 0;
                for (auto x: s) same += st.count(x);
                ans = min(ans,2*n-same-1);
            }
        }
        REP (j,n) {
            set<int> st;
            REP (i,n) st.insert(c[b][i][j]);
            for (auto s: nums[a]) {
                int same = 0;
                for (auto x: s) same += st.count(x);
                ans = min(ans,2*n-same-1);
            }
        }
        {
            set<int> st;
            REP (i,n) st.insert(c[b][i][i]);
            for (auto s: nums[a]) {
                int same = 0;
                for (auto x: s) same += st.count(x);
                ans = min(ans,2*n-same-1);
            }
        }
        {
            set<int> st;
            REP (i,n) st.insert(c[b][i][n-i-1]);
            for (auto s: nums[a]) {
                int same = 0;
                for (auto x: s) same += st.count(x);
                ans = min(ans,2*n-same-1);
            }
        }
    }
    ans = max(ans,n);
    printf("%d\n",ans);
    return 0;
}