package yukicoder;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Q452 {
	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.next());
		int m = Integer.parseInt(sc.next());
		int[][][] table = new int[m][n][n];
		for (int i = 0; i < m; ++i) {
			for (int j = 0; j < n; ++j) {
				for (int k = 0; k < n; ++k) {
					table[i][j][k] = Integer.parseInt(sc.next());
				}
			}
		}
		ArrayList[][] list = new ArrayList[m][2 * n + 2];
		for (int i = 0; i < list.length; ++i) {
			for (int j = 0; j < list[i].length; ++j) {
				list[i][j] = new ArrayList<>();
			}
		}

		for (int i = 0; i < m; ++i) {
			int p = 0;
			for (int j = 0; j < n; ++j) {
				for (int k = 0; k < n; ++k) {
					list[i][p].add(table[i][j][k]);
					list[i][p + 1].add(table[i][j][k]);
				}
				p += 2;
				list[i][2 * n].add(table[i][j][j]);
				list[i][2 * n + 1].add(table[i][n - 1 - j][j]);
			}
		}

		int min = Integer.MAX_VALUE;
		for (int i = 0; i < m; ++i) {
			for (int j = i + 1; j < m; ++j) {
				for (ArrayList<Integer> list1 : list[i]) {
					boolean[] vis = new boolean[n * n * m + 1];
					for (int set1 : list1) {
						vis[set1] = true;
					}
					for (ArrayList<Integer> list2 : list[j]) {
						int count = 0;
						for (int set2 : list2) {
							if (vis[set2]) {
								++count;
							}
						}
						min = Math.min(2 * n - count - 1, min);
					}
				}
			}
		}
		System.out.println(min);
	}
}