import java.io.PrintStream;
import java.util.Arrays;
import java.util.Scanner;

public class Y452 {
	Scanner in = new Scanner(System.in);
	PrintStream out = new PrintStream(System.out);
	int n, m;
	int[][][] c;
	Y452() throws Exception {
		n = in.nextInt();
		m = in.nextInt();
		
		c = new int[m][n][n];
		
		for (int i = 0; i < m; i++) {
			for (int x = 0; x < n; x++) {
				for (int y = 0; y < n; y++) {
					c[i][x][y] = in.nextInt();
				}
			}
		}
		
		
		int fit = 0;
		for (int i = 0; i < m; i++) {
			for (int j = 0; j < 2 * n + 2; j++) {
				int[] a = line(i, j);
				
				for (int x = 0; x < i; x++) {
					for (int y = 0; y < 2 * n + 2; y++) {
						int[] b = line(x, y);
						fit = Math.max(fit, fit(a, b));
					}
				}
			}
		}
		
		out.println(2 * n - 1 - fit);
	}
	
	int[] line(int id, int k) {
		int[] ar = new int[n];
		
		if (k < n) {
			for (int i = 0; i < n; i++) {
				ar[i] = c[id][k][i];
			}
			return ar;
		}
		k -= n;
		if (k < n) {
			for (int i = 0; i < n; i++) {
				ar[i] = c[id][i][k];
			}
			return ar;
		}
		k -= n;
		if (k == 0) {
			for (int i = 0; i < n; i++) {
				ar[i] = c[id][i][i];
			}
			return ar;
		} else {
			for (int i = 0; i < n; i++) {
				ar[i] = c[id][n - 1 - i][i];
			}
			return ar;
		}		
	}
	
	int fit(int[] a, int[] b) {
		Arrays.sort(a);
		Arrays.sort(b);
		int fit = 0;
		for (int i = 0, j = 0; i < n; i++) {
			while (j < n && b[j] < a[i]) {
				j++;
			}
			if (j < n && a[i] == b[j]) {
				fit++;
			}
		}
		return fit;
	}

	public static void main(String argv[]) throws Exception {
		new Y452();
	}
}