#include<iostream>
#include<vector>
#include<string>
#include<cstring>
#include<algorithm>
#include<map>
#include<set>
#include<cmath>
#include<cassert>
#include<queue>

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;

const int MAXM = 222;
const int MAXN = 111;

int C[MAXM][MAXN][MAXN];
bool done[MAXN][MAXN];
int N, M;

int cnt() {
	int ret = N;
	for (int i = 0; i < N; i++) {
		int tmp = 0;
		for (int j = 0; j < N; j++) {
			if (done[i][j]) ++tmp;
		}
		ret = min(ret, N-tmp);
	}
	for (int j = 0; j < N; j++) {
		int tmp = 0;
		for (int i = 0; i < N; i++) {
			if (done[i][j]) ++tmp;
		}
		ret = min(ret, N-tmp);
	}
	int tmp = 0;
	for (int i = 0; i < N; i++) {
		if (done[i][i]) ++tmp;
	}
	ret = min(ret, N-tmp);
	tmp = 0;
	for (int i = 0; i < N; i++) {
		if (done[i][N-1-i]) ++tmp;
	}
	ret = min(ret, N-tmp);
	return ret;
}

int calc(int a, int b) {
	int ans = N-1;
	for (int i = 0; i < N; i++) {
		set<int> S;
		for (int j = 0; j < N; j++) {
			S.insert(C[a][i][j]);
		}
		memset(done, false, sizeof(done));
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				if (S.find(C[b][i][j]) != S.end()) done[i][j] = true;
			}
		}
		ans = min(ans, cnt()-1);
	}
	for (int j = 0; j < N; j++) {
		set<int> S;
		for (int i = 0; i < N; i++) {
			S.insert(C[a][i][j]);
		}
		memset(done, false, sizeof(done));
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				if (S.find(C[b][i][j]) != S.end()) done[i][j] = true;
			}
		}
		ans = min(ans, cnt()-1);
	}
	{
		set<int> S;
		for (int i = 0; i < N; i++) {
			S.insert(C[a][i][i]);
		}
		memset(done, false, sizeof(done));
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				if (S.find(C[b][i][j]) != S.end()) done[i][j] = true;
			}
		}
		ans = min(ans, cnt()-1);
	}
	{
		set<int> S;
		for (int i = 0; i < N; i++) {
			S.insert(C[a][i][N-1-i]);
		}
		memset(done, false, sizeof(done));
		for (int i = 0; i < N; i++) {
			for (int j = 0; j < N; j++) {
				if (S.find(C[b][i][j]) != S.end()) done[i][j] = true;
			}
		}
		ans = min(ans, cnt()-1);
	}
	return ans+N;
}

int main() {
	cin >> N >> M;
	for (int i = 0; i < M; i++) {
		for (int j = 0; j < N; j++) {
			for (int k = 0; k < N; k++) {
				cin >> C[i][j][k];
			}
		}
	}
	int ans = 2*N-1;
	for (int i = 0; i < M; i++) {
		for (int j = i+1; j < M; j++) {
			ans = min(ans, calc(i, j));
		}
	}
	cout << ans << endl;
	return 0;
}